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The Cisco VSC2700 network solution is based on the Cisco Open Packet Telephony (OPT) architecture and provides switched voice services over data networks. The solution teams the Cisco VSC2700 Virtual Switch Controller with Cisco gateways to create a virtual switch network that performs functions of a multi-service transmission network and a time-division multiplexing (TDM) tandem switch. The multi-service network can be an enterprise campus, a metropolitan-area network (MAN), and a wide area network (WAN).
| Acronym | Description |
|---|---|
AAA | Authentication, authorization, and accounting. Set of functions on the network access server providing authentication, authorization, and accounting for system and network resources. |
AAL | ATM adaptation layer. Service-dependent sublayer of the data link layer. The AAL accepts data from different applications and presents it to the ATM layer in the form of 48 bytes ATM payload segments. AALs consist of two sublayers: CS and SAR. AALs differ on the basis of the source-destination timing used, whether they use CBR or VBR, and whether they are used for connection-oriented or connectionless mode data transfer. |
AAL1 | ATM adaptation layer 1. One of four AALs recommended by the ITU-T. AAL1 is used for connection-oriented, delay-sensitive services requiring constant bit rates, such as uncompressed video and other isochronous traffic. See also AAL. |
ABR | Available bit rate. QoS class defined by the ATM Forum for ATM networks. ABR is used for connections that do not require timing relationships between source and destination. ABR provides no guarantees in terms of cell loss or delay, providing only best-effort service. Traffic sources adjust their transmission rate in response to information they receive describing the status of the network and its capability to successfully deliver data. |
AIN | Advanced Intelligent Network. In SS7, an expanded set of network services made available to the user, and under user control, that requires improvement in network switch architecture, signaling capabilities, and peripherals. |
AMI | Alternate mark inversion. Line-code type used on T1 and E1 circuits. In AMI, zeros are represented by 01 during each bit cell, and ones are represented by 11 or 00, alternately, during each bit cell. AMI requires that the sending device maintain ones density. Ones density is not maintained independent of the data stream. Sometimes called binary coded alternate mark inversion. |
ATM | Asynchronous Transfer Mode. International standard for cell relay in which multiple service types (such as voice, video, or data) are conveyed in fixed-length (53B) cells. Fixed-length cells allow cell processing to occur in hardware, thereby reducing transit delays. ATM is designed to take advantage of high-speed transmission media, such as E3, SONET, and T3. |
ATM layer | Service-independent sublayer of the data link layer in an ATM network. The ATM layer receives the 48 bytes payload segments from the AAL and attaches a 5 bytes header to each, producing standard 53 bytes ATM cells. These cells are passed to the physical layer for transmission across the physical medium. See also AAL. |
B8ZS | Binary 8-zero substitution. Line-code type, used on T1 and E1 circuits, in which a special code is substituted whenever 8 consecutive zeros are sent over the link. This code is then interpreted at the remote end of the connection. This technique guarantees ones density independent of the data stream. Sometimes called bipolar 8-zero substitution. |
BH | Busy Hour. The peak 60-minute period during a business day when the network handles the largest volume of traffic. |
CBR | Constant Bit Rate. QoS class defined by the ATM Forum for ATM networks. CBR is used for connections that depend on precise clocking to ensure undistorted delivery. |
CCS | Common channel signaling. Signaling system used in telephone networks that separates signaling information from user data. A specified channel is exclusively designated to carry signaling information for all other channels in the system. |
CDVT | Cell delay variation tolerance. In ATM, a QoS parameter for managing traffic that is specified when a connection is set up. In CBR transmissions, CDVT determines the level of jitter that is tolerable for the data samples taken by the PCR. |
CES | Circuit emulation service. Enables users to multiplex or concentrate multiple circuit emulation streams for voice and video with packet data on a single high-speed ATM link without a separate ATM access multiplexer. |
CLI | Command line interface. The basic Cisco IOS configuration and management interface. |
CO | Central office. Local telephone company office to which all local loops in a given area connect and in which circuit switching of subscriber lines occurs. |
CODEC | Coder-decoder. Device that typically uses pulse code modulation to transform analog signals into a digital bit stream and digital signals back into analog. |
CPCS | Common part convergence sublayer. One of the two sublayers of any AAL. The CPCS is service-independent and is further divided into the CS and the SAR sublayers. The CPCS is responsible for preparing data for transport across the ATM network, including the creation of the 48-byte payload cells that are passed to the ATM layer. See also AAL, ATM layer, CS, SAR, and SSCS. |
CS | Convergence sublayer. One of the two sublayers of the AAL CPCS, which is responsible for padding and error checking. PDUs passed from the SSCS are appended with an 8 bytes trailer (for error checking and other control information) and padded, if necessary, so that the length of the resulting PDU is divisible by 48. These PDUs are then passed to the SAR sublayer of the CPCS for further processing. See also AAL, CPCS, SAR, and SSCS. |
CSU | Channel service unit. Digital interface device that connects end-user equipment to the local digital telephone loop. Often referred to together with DSU, as CSU/DSU. See also DSU. |
CTI | Computer telephony integration. Name given to the merger of traditional telecommunications (PBX) equipment with computers and computer applications. The use of caller ID to automatically retrieve customer information from a database is an example of a CTI application. |
DCE | 1. Data communications equipment (EIA expansion). 2. Data circuit-terminating equipment (ITU-T expansion). Devices and connections of a communications network that comprise the network end of the user-to-network interface. The DCE provides a physical connection to the network, forwards traffic, and provides a clocking signal used to synchronize data transmission between DCE and DTE devices. Modems and interface cards are examples of DCE. Compare with DTE. |
DCS | Digital Crossconnect system. Network element providing automatic cross connection of a digital signal or its constituent parts. |
DPNSS | Digital Private Network Signaling System. Proprietary BT protocol for PBXs (digital private network) signaling system. |
DS-0 | Digital Signal Level Zero. Framing specification used in transmitting digital signals over a single channel at 64 kbps on a T1 facility. |
DSL | Digital subscriber line. Public network technology that delivers high bandwidth over conventional copper wiring at limited distances. There are four types of DSL: ADSL, HDSL, SDSL, and VDSL. All are provisioned via modem pairs, with one modem located at a central office and the other at the customer site. Because most DSL technologies do not use the whole bandwidth of the twisted pair, there is room remaining for a voice channel. |
DSU | Data service unit. Device used in digital transmission that adapts the physical interface on a DTE device to a transmission facility such as T1 or E1. The DSU is also responsible for such functions as signal timing. Often referred to together with CSU as CSU/DSU. See also CSU. |
DTE | Data terminal equipment. Device at the user end of a user-network interface that serves as a data source, destination, or both. DTE connects to a data network through a DCE device (for example, a modem) and typically uses clocking signals generated by the DCE. DTE includes such devices as computers, protocol translators, and multiplexers. |
Erlang | Unit of traffic intensity. One Erlang is the intensity at which one traffic path is continuously occupied. |
FDDI | Fiber Distributed Data Interface. Specifies a 100 Mbps token-passing, dual-ring LAN using fiber-optic cable. |
FDM | Frequency-division multiplexing. Technique whereby information from multiple channels can be allocated bandwidth on a single wire based on frequency. |
H.320 | Suite of ITU-T standard specifications for video conferencing over circuit-switched media such as ISDN, fractional T1, or switched-56 lines. |
LAN | Local-area network. High-speed, low-error data network covering a relatively small geographic area (up to a few thousand meters). LANs connect workstations, peripherals, terminals, and other devices in a single building or other geographically limited area. LAN standards specify cabling and signaling at the physical and data link layers of the OSI model. Ethernet, FDDI, and Token Ring are widely used LAN technologies. |
MAN | Metropolitan-area network. A network that spans a metropolitan area. Generally, a MAN spans a larger geographic area than a LAN, and a smaller geographic area than a WAN. |
NSAP | Network Service Access Point. |
PBX | Private branch exchange. Digital or analog telephone switchboard located on the subscriber premises and used to connect private and public telephone networks. |
PCM | Pulse code modulation.Transmission of analog information in digital form through sampling and encoding the samples with a fixed number of bits. Either -law ("mu" law, used in USA and Japan) or a-law (used in other countries). |
PCR | Peak cell rate. Parameter defined by the ATM Forum for ATM traffic management. In CBR transmissions, PCR determines how often data samples are sent. In ABR transmissions, PCR determines the maximum value of the ACR. See also ABR, ACR, and CBR. |
PNNI | 1. Private Network-Network Interface. ATM Forum specification for distributing topology information between switches and clusters of switches that is used to compute paths through the network. The specification is based on well-known link-state routing techniques and includes a mechanism for automatic configuration in networks in which the address structure reflects the topology. 2. Private Network Node Interface. ATM Forum specification for signaling to establish point-to-point and point-to-multipoint connections across an ATM network. The protocol is based on the ATM Forum UNI specification with additional mechanisms for source routing, crankback, and alternate routing of call setup requests. |
PSTN | Public Switched Telephone Network. General term referring to the variety of telephone networks and services in place worldwide. Sometimes called POTS. |
PVC | Permanent virtual connection. Virtual circuit that is permanently established. PVCs save bandwidth associated with circuit establishment and tear down in situations where certain virtual circuits must exist all the time. In ATM terminology, called a permanent virtual connection. |
QoS | Quality of service. Measure of performance for a transmission system that reflects its transmission quality and service availability. |
SAR | Segmentation and reassembly. One of the two sublayers of the AAL CPCS, responsible for dividing (at the source) and reassembling (at the destination) the PDUs passed from the CS. The SAR sublayer takes the PDUs processed by the CS and, after dividing them into 48 bytes pieces of payload data, passes them to the ATM layer for further processing. See also AAL, ATM layer, CPCS, CS, and SSCS. |
SCR | Sustained cell rate. Parameter defined by the ATM Forum for ATM traffic management. For VBR connections, SCR determines the long-term average cell rate that can be transmitted. |
SGCP | Simple Gateway Control Protocol. Controls Voice over IP gateways by an external call control element (called a call-agent). This has been adapted to allow SGCP to control switch ATM Circuit Emulation Service circuits (called endpoints in SGCP). The resulting system (call-agents and gateways) allows for the call-agent to engage in Common Channel Signaling (CCS) over a 64 Kbps CES circuit, governing the interconnection of bearer channels on the CES interface. |
SIP | 1. SMDS Interface Protocol. Used in communications between CPE and SMDS network equipment. Allows the CPE to use SMDS service for high-speed WAN internetworking. Based on the IEEE 802.6 DQDB standard. 2. Serial Interface Processor. |
SS7 | Signaling System 7. Standard CCS system used with BISDN and ISDN. Developed by Bellcore. See also CCS. |
SSCS | Service Specific Convergence Sublayer. One of the two sublayers of any AAL. SSCS, which is service dependent, offers assured data transmission. The SSCS can be null as well, in classical IP over ATM or LAN emulation implementations. See also AAL, ATM layer, CPCS, CS, and SAR. |
TDM | Time-division multiplexing. Technique in which information from multiple channels can be allocated bandwidth on a single wire based on preassigned time slots. Bandwidth is allocated to each channel regardless of whether the station has data to transmit. |
TR-303 | Bellcore technical recommendation for DCL (digital customer loop) signaling. |
TINA-C | Telecommunications Information Networking Architecture. Services applications built in C and corresponding to TINA guidelines. |
UNI | User-Network Interface. ATM Forum specification that defines an interoperability standard for the interface between ATM-based products (a router or an ATM switch) located in a private network and the ATM switches located within the public carrier networks. Also used to describe similar connections in Frame Relay networks. |
VCI | Virtual channel identifier. This is a 16 bytes field in the header of an ATM cell. The VCI, together with the VPI, is used to identify the next destination of a cell as it passes through a series of ATM switches on its way to its destination. ATM switches use the VPI/VCI fields to identify the next network VCL that a cell needs to transit on its way to its final destination. The function of the VCI is similar to that of the DLCI in Frame Relay. See also VCL and VPI. |
VCL | Virtual channel link. Connection between two ATM devices. A VCC is made up of one or more VCLs. See also VCC. |
VPI | Virtual Path Identifier. This is a 8 bytes field in the header of an ATM cell. The VPI, together with the VCI, is used to identify the next destination of a cell as it passes through a series of ATM switches on its way to its destination. ATM switches use the VPI/VCI fields to identify the next VCL that a cell needs to transit on its way to its final destination. The function of the VPI is similar to that of the DLCI in Frame Relay. |
Cisco VSC2700 | Cisco's Virtual switch controller. Performs signaling processing and call control functions within the system. |
WAN | Wide-area network. Data communications network that serves users across a broad geographic area and often uses transmission devices provided by common carriers. Frame Relay, SMDS, and X.25 are examples of WANs. |
Open Packet Telephony (OPT) is Cisco's three-layer architecture that provides a framework for the integration of traditional telephony over data infrastructures. This integration is handled efficiently with minimal overhead and allows for the seamless integration of traditional voice networks.
The most important characteristic of the OPT architecture is the clean separation of call control from the switching fabric. This split was achieved by the definition of an open interface between the two functional layers. Historically, the call control and switching functions have been tightly coupled in traditional TDM systems. This leaves service providers with little control over switching functions and an almost complete dependence on the switching manufacturers for enhancements.
The three layers of the OPT architecture are:
As you can see in Figure 1, these layers are arranged in a hierarchy and interact with each other using open, standardized interfaces.
Table 2 describes the functionality of the three layers.
| Layer | Description |
|---|---|
Service control layer | Provides enhanced services logic and consists of traditional Service Control Point (SCP) devices and new and third-party Cisco applications. |
Call control layer | Terminates TDM signaling information, translates dialed digits into packet addresses, and sends commands to the Transport layer necessary to establish a call. Other centralized functions such as CDR generation and service provisioning are handled at this layer. |
Transport layer | Creates, modifies, and deletes call sessions based on instructions from the Call control layer. It is also responsible for ensuring the quality of service (QoS). |
The Cisco VSC2700 performs the duties at the Call control layer while trunking gateways create call sessions at the Transport layer. The term trunking gateway refers to a new class of ATM switches or IP routers. In addition to their traditional data functions, these devices have been enhanced to support packetizing the voice traffic and setting up calls across the data network. The Cisco Catalyst 8500 Series Multiservice Switching Routers (MSR) serve as trunking gateways. For details, refer to "ATM Switches (Trunking Gateways)" later in this document.
Table 3 describes the benefits of an OPT deployment over a traditional TDM network.
| Benefit | Description |
|---|---|
Fabric independence | The open interface between the Transport and Call control layer allows Call control devices like the Cisco VSC2700 to manage call sessions across data infrastructures including transports such as IP, ATM, Frame, and cable. |
Open standards | The OPT architecture is based on open industry standards jointly defined by Bellcore and Cisco Systems. One of the key standards in the OPT architecture defines the interface between the Transport layer and the Call Control layer. This interface is the Simple Gateway Control Protocol (SGCP). (For a brief overview of SGCP, see "Gateway Control Protocol Overview" later in this section.) The Cisco VSC2700 uses this protocol to communicate with trunking gateways. In addition, other standards such as Media Gateway Control Protocol (MGCP) are picking up where SGCP leaves off. Cisco Systems is working closely with other industry leaders to finalize the definition of MGCP. |
Faster deployment | Because the OPT architecture is based on open standards, deploying new services is much more rapid than on closed proprietary architectures. Furthermore, open architectures typically cost less than proprietary solutions, because open standards encourage competition between suppliers. |
Multiple services | Bringing voice and data together on a single network lowers both the operational overhead associated with managing multiple networks, and the bandwidth requirements due to the benefits of statistical multiplexing. |
Rapid service provisioning | New services can be provisioned and managed rapidly in the OPT architecture since call control logic is organized in a centralized or semi-distributed topology rather than at each switching device. For example, dial plans are managed centrally at the Cisco VSC2700 so updates across numerous switching platforms are not necessary. |
Asynchronous Transfer Mode (ATM) is a standard for cell relay created by the former Consultative Committee for International Telegraph and Telephone (CCITT) now known as the International Telecommunication Union Telecommunication Standardization Sector [ITU-T]. This standard defines how information for multiple service types (such as voice, video, or data) is conveyed.
ATM combines the benefits of circuit switching (guaranteed capacity and constant transmission delay) with those of packet switching (flexibility and efficiency for intermittent traffic). It provides scalable bandwidth from a few Mbps to many Gbps. Because it is asynchronous, ATM is more efficient than synchronous technologies like time-division multiplexing (TDM).
ATM is based on the efforts of the ITU-T Broadband Integrated Services Digital Network (BISDN) standard. It was developed as a high-speed transfer technology for voice, video, and data over public networks.
ATM transfers information in fixed-size units called cells. Each cell consists of 53 bytes. The first 5 bytes contain cell header information, and the remaining 48 bytes contain the payload (user information). Small fixed-length cells are well-suited to transferring voice and video traffic. Such traffic is intolerant of delays that could result from having to wait for a large data packet to be transmitted.
An ATM network consists of two main components:
An ATM switch is responsible for cell transit through an ATM network. The job of an ATM switch is well-defined:
1. Accept the incoming cell from an ATM endpoint or another ATM switch.
2. Read and update the cell header information.
3. Quickly switch the cell to an output interface toward its destination.
An ATM endpoint (or endsystem) contains an ATM network interface adapter. Examples of ATM endpoints are workstations, routers, data service units (DSUs), LAN switches, and video coder-decoder (CODEC).
Figure 3 shows an ATM network made up of ATM switches and ATM endpoints.
An ATM network consists of a set of ATM switches interconnected by point-to-point ATM links or interfaces. ATM switches support two primary types of interfaces:
Depending on whether the switch is owned and located at the customer premise, or publicly owned and operated by the telco, UNI and NNI can be further subdivided as follows:
An additional specification, the Broadband Interexchange Carrier Interconnect (B-ICI), connects two public switches from different service providers.
Figure 4 shows the ATM interface specifications for private and public networks.
There are three types of ATM services:
ATM networks are fundamentally connection oriented. This means that a virtual channel (VC) needs to be set up across the ATM network prior to any data transfer. (A virtual channel is roughly equivalent to a virtual circuit.) ATM connections are of two types:
A virtual path is a bundle of virtual channels, all of which are switched transparently across the ATM network on the basis of the common VPI. The VPI of a virtual path has only local significance across a particular link, and are remapped, as appropriate, at each switch.
Figure 5 shows how VCs concatenate to create VPs, which in turn, concatenate to create a transmission path.
This section briefly describes the protocols used in the Cisco VSC2700 network solution:
See the following sections for a brief discussion of both protocols.
The Cisco VSC2700 (located on the middle layer of OPT) uses the Simple Gateway Control Protocol (SGCP) to control the Voice over IP (VoIP) gateways. The following SGCP messages are exchanged between the Cisco VSC2700 and the Cisco Catalyst 8500 Series MSR gateways.
| SGCP Message | Purpose |
|---|---|
CreateConnection | Used by the Cisco VSC2700 to allocate bearer channels on the trunking gateway CES interfaces, and set up an ATM Soft PVC to connect the bearer channels. |
DeleteConnection | Used by the Cisco VSC2700 to release a bearer channel on a CES interface and clear any associated Soft PVCs. |
The Cisco Catalyst 8500 Series MSR sets up point-to-point bidirectional connections.
For details, refer to the following documents:
Multiple Cisco VSC2700s communicate using a Cisco protocol based on ISUP known as Extended ISUP (E-ISUP). E-ISUP uses a subset of ISUP messages.
The E-ISUP message formatting contains many of the same characteristics of the existing ISUP message format. The primary difference between existing ISUP and E-ISUP messages is in the area of the routing label and a new information element (IE) to carry CU-related data between Cisco VSC2700s.
The Originating Point Code (OPC) and the Destination Point Code (DPC) in the routing label is replaced with the originating Cisco VSC2700 address and the destination Cisco VSC2700 addresses. The CIC is replaced with a Global Call Reference (GCR) generated by the originating Cisco VSC2700.
E-ISUP uses a reliable IP as its transport layer. Table 4 lists the ISUP messages supported in E-ISUP.
| Message | Acronym | Usage |
|---|---|---|
Initial Address Message | IAM | Similar to the ISUP IAM. In addition to ISUP IEs for A-number, B-number, and bearer capabilities, the IAM carries a Connection Descriptor end-to-end. This field is necessary for Cisco VSC2700s to communicate connection information to CUs. An ISUP Generic Digits IE is used to deliver this information. |
Address Complete Message | ACM | Similar to the ISUP ACM. In addition to ISUP IEs the ACM carries a Connection Descriptor end-to-end. This field is necessary for Cisco VSC2700s to communicate connection information to CUs. Extended ISUP supports the ISUP Generic Digits IE as an extension to the standard IEs defined in ISUP. |
Subsequent Address Message | SAM | Similar to the ISUP ANM. See the following item. |
Answer Message | ANM | Similar to the ISUP ANM. In addition to ISUP IEs, the ANM carries a Connection Descriptor end-to-end. This field is necessary for Cisco VSC2700s to communicate connection information to CUs. Extended ISUP supports the ISUP Generic Digits IE as an extension to the standard IEs defined in ISUP. |
Release Message | REL | Similar to the ISUP REL. In addition to ISUP IEs the REL message will carry a Connection Descriptor end-to-end. This field is necessary for Cisco VSC2700s to communicate connection information to CUs. An ISUP Generic Digits IE is used to deliver this information. |
Release Complete Message | RLC | Similar to the ISUP RLC. Presently no additional IEs are required for Extended ISUP. |
The Cisco VSC2700 solution provides a cost-effective call control plane for packet telephony. The Cisco VSC2700 is central to the OPT architecture and is responsible for receiving call setup messages from traditional TDM networks, translating the requests to meaningful instructions that the data network can interpret and act upon. The instructions allow calls to be switched across a data network.
In addition, the Cisco VSC2700 produces a wide range of easily readable feedback on how well it and the network are performing. For example, it produces call detail information on a call-by-call basis. Each CDR contains specific information regarding the call, mirroring traditional telco type CDRs.
The Cisco VSC2700 draws its power from a unique patented approach to signaling processing. Commonly referred to as the Universal Call Model (UCM), the Cisco VSC2700 employs a two-step approach to processing incoming messages. This allows the Cisco VSC2700 to interwork a wide variety of signaling protocols. Supporting the UCM is a Cisco programming language called Message Definition Language (MDL) which is specifically designed for the rapid creation of interworking protocols.
Designed as a global product, the Cisco VSC2700 supports a number of user-to-network protocols, including ESTI PRI, ITU Q.931, Q.SIG, NI-2, AT&T 41459, and DPNSS.
The Cisco VSC2700 network solution consists of the Cisco VSC2700 working in conjunction with Cisco Catalyst 8500 Series MSR gateways to support the switching of voice on demand over an ATM enterprise campus, a MAN, or a WAN. Figure 6 displays a typical network implementation with two Cisco VSC2700s, each connected to a trunking gateway (Cisco Catalyst 8500 Series MSR) and the IP network used for signaling.
Each gateway is connected to multiple PBXs. The gateway receive PRI signal messages from the PBXs and send them to the Cisco VSC2700. The gateway also receives the payload (voice, video, and data) and using the CES Port Adapter Modules (PAM), sends it out over the ATM network.
The Cisco VSC2700 makes routing and bandwidth allocation decisions about each call and sends control messages to the relevant CUs using SGCP. All calls are set up on an as-needed basis.
This section briefly describes the features supported by the Cisco VSC2700 network solution.
This solution supports the three types of calls described in Table 5.
| Origination | Termination | Scenario |
|---|---|---|
PBX | PBX | A device on a directly attached PBX to another device on another directly attached PBX. The call originates and terminates within the enterprise network. |
PBX | PSTN | A device on a directly attached PBX to another device located in the public network. The call originates inside the enterprise network and terminates in the PSTN. |
PSTN | PBX | A device located in the PSTN to a device on a directly attached PBX. The call originates outside in the PSTN and terminates in the enterprise network. |
Table 6 lists the network features supported by the Cisco VSC2700 network solution.
| Feature | Support for... |
|---|---|
Number of Cisco VSC2700s on one network | Unlimited |
Number of gateways | Unlimited |
Number of gateways supported by a single Cisco VSC2700 | Depends on the average call duration and number of voice interfaces per gateway |
Switched voice service | 64 KB soft PVC for call duration |
Data services | Gateway ATM data services |
ATM QoS support | Gateway ATM QoS support |
External network interfaces | Gateway interfaces |
Signaling protocols support | Cisco VSC2700 signaling protocols support |
Gateway control protocol | Bellcore and Cisco SGCP |
PRI signaling transport from gateway to co-located Cisco VSC2700 | TDM E1/T1 |
PRI signaling transport gateway to remote Cisco VSC2700 (via co-located gateway) | 64 KB PVC or soft PVC |
SGCP transport | UDP on IP |
These are the supported PBX common-channel signaling protocols:
The current generation of CES PAMs available do not support echo cancellation. In general, you do not require echo cancellation within a confined geographical area, such as a campus or MAN. For situations where echo cancellation is required, you can deploy an external echo cancellation device in your network.
Also, note that the same is true for voice compression. The transport for the switched call is the CBR AAL1 Soft PVC at 64 K. The solution is targeted at campus, MAN and high-speed WAN networks where the need for compression is minimal. In addition, because the transport is effectively TDM, voice, H.320 video and ISDN data calls can be provisioned over the solution. The solution introduces efficiencies as the bandwidth is now delivered on demand as opposed to being permanently statically assigned.
The following current generation of CES PAMs are supported for the Cisco Catalyst 8500 Series MSR:
The Transport layer contains one or more of the following Cisco ATM switches (also referred to as trunking gateways in OPT architecture):
The multiservice routing switches perform the following trunking gateway functions:
For graphical representations of the gateways and a list of reference documentation, refer to the section "ATM Switches (Trunking Gateways)" later in this document.
This section briefly describes the network interfaces between the elements of the Cisco VSC2700 network solution. For details, refer to the appropriate documentation.
Figure 7 displays a typical network implementation with two Cisco VSC2700s, each connected to a trunking gateway (Cisco Catalyst 8500 Series MSR) and the IP network using for signaling.
This interface is used between the following network elements:
The Soft PVC protocol is used between the following network elements:
The 10BaseT/100BaseT Ethernet interface is used between the following network elements:
This section displays examples of call flows. In the following example, two PBXs are connected to two Cisco LS1010s, which are managed by separate Cisco VSC2700s. Further, both PBXs use the ETSI PRI access protocol. Note that typically other than the access and egress protocols all other aspects of the call flows depicted in this section will apply to most customers.
Figure 8 shows a call flow for a circuit setup using CreateConnection commands.
In Figure 8:
1. After the Cisco VSC2700 receives a Setup message, the Cisco VSC2700 instructs the Coding Unit (CU), in this case the Cisco LS1010, to reserve the TDM circuit identified in the message. This is done using the SGCP command CreateConnection. At this stage, the connection mode is specified as inactive (that is, the circuit is reserved but no data transfer takes place).
Once this function is completed successfully and an acknowledgment (Ack) message is received, the Cisco VSC2700 then analyses the delivered destination number to determine how to route the call. In this case, the Cisco VSC2700 selects the route to another Cisco VSC2700 and then issues an LISUP IAM message to that Cisco VSC2700.
2. When the terminating Cisco VSC2700 receives the LISUP IAM message, it first analyses the received destination number and then determines where the call will terminate (the terminating Cisco LS1010), and the TDM route and signaling channel from that Cisco LS1010. The Cisco VSC2700 also allocates a bearer channel (if one is available) for this call.
The Cisco VSC2700 then instructs the Cisco LS1010 to create a connection back to the originating Cisco LS1010 (the originating bearer channel), and connect the allocated bearer channel on the terminating Cisco LS1010. The connection across the network is done by creating a Soft PVC setup using an address allocated by the originating Cisco LS1010, returned to the originating Cisco VSC2700 in the Ack message in response to the CreateConnection message, and delivered to the terminating Cisco VSC2700 in the LISUP IAM message.
After an acknowledgment is received from the terminating Cisco LS1010 indicating that all connections have been created, the Cisco VSC2700 sends a Setup message across the signaling channel of the terminating Cisco LS1010.
3. The originating Cisco VSC2700, after receiving positive acknowledgment (LISUP ACM or ANM message) from the far end that the call has been delivered, modifies the attributes of the connection mode on the originating Cisco LS1010 to send and receive so that full duplex data transfer can take place once the call is answered.
Figure 9 displays a scenario in which the call release is initiated via one of the telephony devices going on hook (in this case the originating device).
Figure 10 displays a scenario in which the Cisco LS1010 initiates the release of the call due to a network failure. Due to the network failure, both gateways receive a release instruction for the Soft PVC, which results in an SGCP instruction to the Cisco VSC2700 to delete the connection instance.
Figure 11 displays the operational support systems used to manage and configure the Cisco VSC2700 network solution.
Table 7 briefly describes the support applications used to manage and configure the network solution.
| Application | Description |
|---|---|
Configuration Tool (CT) and Dial Provisioning Plan | CT is the Cisco VSC2700 configuration and provisioning tool. You can access the CT remotely using a Java-enabled web browser and manage all the Cisco VSC2700s in a network with a single CT system. DPP is used to format the dial plan and routing data for deployment on the Cisco VSC2700s. Dial plan and routing data is defined in a flat file and this information is parsed by the DPP to generate the configuration files for deployment on the Cisco VSC2700s. The applications are installed on a PC with Microsoft Windows NT 4.0 (server edition if DNS required). The network interface is 10BaseT/100BaseT Ethernet. |
CiscoView | The CiscoView graphical user interface (GUI) device management application provides dynamic status, statistics, and configuration information for the Cisco gateways. Note that there is currently no MIB support for CES and you need to use the Command Line Interface (CLI) for most provisioning functions. The application runs on a Sun Sparc Station or HP/Apollo Series 700 running Sun OS 4.1.3 or Solaris 2.4 on the Sun machines and HP-UX 9.03, 9.04, or 9.05 on the HP machines. You have the following network interface connection options:
|
AtmDirector | AtmDirector is a graphical, system-level ATM management application for configuring, monitoring, and troubleshooting a network of Cisco ATM switches and ATM-attached Cisco routers and Catalyst LAN switches. The AtmDirector application automatically discovers and illustrates the topology of the ATM network, displays real-time link information, facilitates ATM network interrogation and troubleshooting by allowing selection of any virtual connection on an ATM link and tracing its entire path, and provides an intuitive interface for creating PVCs across the ATM network. You can integrate the AtmDirector with popular SNMP management platforms or use it as a fully functional, independent ATM network management application. ATM management functions provide real-time status, statistics, and configuration information, allowing the administrator to more easily understand and use the complex management data available for ATM networks. The application runs on a customer-provided Windows NT Server. The network interface is 10BaseT/100BaseT Ethernet. |
Customer Functions | These include customer systems required for operational support. For example, billing and management systems, such as HP OpenView and SunNet Manager. The network interface is 10BaseT/100BaseT Ethernet. |
Customer Workstation/PC | MML, MMI, and CLI access is provided to all network elements and is required for some operational tasks on the Cisco VSC2700 and gateways. Also, access to the CT is provided for JAVA-enabled Web clients so that you can make configuration changes remotely. This can be installed on a PC (connected to your LAN) or workstation and includes the TCP/IP protocol suite (Telnet, rlogin, and ftp) and a JAVA-enabled web browser, such as Netscape Navigator 4.0. The network interface is Ethernet 10/100BaseT. |
This section discusses two solutions:
Both solutions are discussed in the following sections.
The enterprise solution consists of the deployment of an ATM MAN or campus network capable of providing both data and switched voice services. Cisco trunking gateways at each location assemble data traffic from the LAN and the voice traffic from the PBX into one ATM stream and send it to the required location over the campus network. Because the Cisco VSC2700 network solution provides both ATM transmission and tandem voice switching functions, it eliminates the need for TDM tandem PBXs.
Enterprise customers with the following characteristics will benefit by deploying a Cisco VSC2700 network solution for voice and data integration:
In the configuration in Figure 12, the customer allocates a portion of the PBX switching resources to switch calls between the various end points. For example, Site 1, 3, and 4 can only call each other by first passing through Site 2. In this case, Site 2 is commonly referred to as a tandem PBX. In networks with a large number of PBXs, the customer could need a PBX just for managing connectivity rather than managing call control.
By deploying the Cisco VSC2700 in combination with the Cisco Catalyst 8500 Series MSR trunking gateways, as shown in Figure 13, the enterprise customer's network can be greatly simplified and operated and managed more efficiently.
With this configuration, you do not need to emulate a T1 or E1 link across an ATM infrastructure. Only the signaling D channel needs to be backhauled to the Cisco VSC2700. The D channel is a single DS0 (Digital Signal level 0) and consumes only 64 K of bandwidth. Signaling channels from multiple PBXs terminate at a single Cisco VSC2700 and the Cisco VSC2700 then informs the underlying infrastructure on a call-by-call basis to cross-connect individual DS0s between the PBXs.
When configured at the Cisco VSC2700, inter-PBX traffic passes over the ATM backbone. Unlike the traditional solution, calls now pass directly between various sites over the meshed data infrastructure. This application is also referred to as tandem replacement.
The elements of this solution include:
The Cisco VSC2700 network solution provides enterprise customers with the following benefits:
The Cisco VSC2700 network solution can be used by service providers to provide a single network access interface to its core bandwidth for the enterprise voice and data traffic. The solution serves as a TDM PRI-to-ATM or ATM-to-ATM interface.
Typically, voice and data networks have been implemented as separate networks. These are all provisioned as separate overlay networks over a TDM core, as shown in Figure 14.
The network displayed in Figure 14 is inefficient in the following ways:
The Cisco VSC2700 network solution uses a single existing data infrastructure for voice and data and as a result, service providers can offer more cost-effective access and extend their geographic reach without deploying expensive traditional systems. As shown in Figure 15, service providers can extend the reach of voice telephony networks by deploying Cisco OPT-enabled data networks at the edge of their networks.
In the above example, end-user voice and data services are terminated directly to the SP data network, which in turn is connected to the traditional TDM SP backbone. Voice calls originating on a customer PBX and requiring inter-PBX routing or IDDD service pass to the trunking gateway where it is packetized and routed based on instructions provided by the Cisco VSC2700.
If the call is destined for a location on the data network, the call simply routes across the data network and terminates on the respective trunking gateway. For calls terminating to a location off the data network, the call passes through the data network where it is handed off to the traditional TDM network backbone for further routing.
The elements necessary for this solution include:
This solution provides the following benefits to service providers:
See the following publications for detailed information:
These publications are available online on the Cisco web site or on the Cisco Documentation CD-ROM that arrived with your system. See the section, "If You Need More Information," and "Cisco Connection Online," for details.
For details on networking and Internet routing refer to the following publications:
The Cisco VSC2700 represents a significant milestone in the evolution of data networks. Now, for the first time, traditional voice services can be seamlessly deployed over a data network packet network infrastructure. The Cisco VSC2700 plays a key role by performing the call control function---terminating traditional TDM signaling, translating dialed digits into data addresses, and establishing a voice quality session on an individual cell basis.
Table 8 lists the features for the Cisco VSC2700.
| Feature | Support for... |
|---|---|
Voice call performance per Cisco VSC2700 | 30 calls per sec |
Number of PRI signaling links per Cisco VSC2700 | 90/72 for E1 and T1 environments |
Support for signaling protocols | ANSI PRI ETSI PRI NI-2 AT&T 41459 PRI ITU Q.931 Alcatel PRI Q.SIG DPNSS |
Signaling interfaces to gateways | E1/T1 |
SGCP and network management interfaces | IP |
Faults and alarms management | SNMP traps External alarm relay unit (ARU) |
Configuration management | GUI based on Java |
Accounting | CDR (CSV format) support for international carrier requirements |
Performance measurements and statistics | Support carrier requirements |
Security | Structured system of passwords |
Operating system | Sun Solaris 2.5.1 |
The primary function of the Cisco VSC2700 is performing call control. The Cisco VSC2700 is responsible for:
For maximum reliability and resilience, we recommend the following options:
You need to consider the following failure conditions for your system:
You can deploy the Cisco VSC2700 in one of two configurations:
See Table 8 for specifications for both configurations.
| Configuration | Description |
|---|---|
Simplex | Single Sun Netra t 1120 host 300 MHz UltraSparc II Processor, PCI bus, 3 slots for interface cards DC powered NEBS level 3 compliant host 256 MB RAM Signaling link I/O cards ARU |
High-Availability | Two Sun Netra t 1120 server hosts (active and standby) 300 MHz UltraSparc II Processor, PCI bus, 3 slots for interface cards DC powered NEBS level 3 compliant host 256 MB RAM Signaling link I/O cards ARU Failover Switch Optional second 10/100BaseT Ethernet |
The Cisco VSC2700 includes the following components:
You can order the Cisco VSC2700 as a single or redundant configuration, as shown in Figure 16.
See Figure 17 for a graphical depiction of a single and dual rack setup with single and dual host configurations. Table 10 lists each element of the vertical rack and the size of each piece of equipment in rack units (RUs), where 1 RU = 1.75 inches.
| Equipment Item | Rack Units (1 RU = 1.75 in.) |
|---|---|
Reserved for customer-provided power | 6 RU |
120 ohm patch panel | 3 RU |
Reserved for customer-provided Ethernet hub | 1 RU |
Failover control box | 5 RU |
Barrier strip | 2 RU |
ARU | 1 RU |
Serial port expander | 2 RU |
Cisco VSC2700 host | 3 RU |
Empty space | 7 RU |
The Cisco VSC2700 includes a scalable, open host that provides signaling interfaces, alarms, and a reliable IP link between the Cisco VSC2700 and gateways. This release offers the Sun Netra 1120t.
The Sun Netra is a general purpose Sun Ultra SPARC server. It has four PCI slots, of which three accept E1, T1, or V.35 cards. (The fourth slot is used as a port extruder.) The Netra is rack-mountable and is NEBS and ETSI compliant.
Table 11 lists the Sun Netra 1120t specifications.
| Feature | Description |
|---|---|
Processor | 1 SPARC Version 9, 300 MHz UltraSPARC-II processor |
Main Memory | 512 MB maximum (with 32 MB SIMMs in pairs) |
Operating System | Sun Solaris 2.5.1 |
Interfaces |
|
Network | Ethernet/Fast Ethernet, STP (10 BaseT and 100 BaseT) or MII for external transceiver |
I/O | 40 MB/sec UltraSCSI (SCSI-3 synchronous) |
Serial | Two EIA/TIA RS-232C or EIA/TIA RS-423 serial ports (DB25) |
Parallel | Centronics-compatible parallel port (DB25) |
PCI | Four full-size PCI with PCI specification version 2.1; three slots operating at 33 MHz, 32- or 64-bit data width; one slot operating at 33 or 66 MHz |
Alarm card | DB-15-pin connector; three dry contact outputs (minor, major, critical); external reset input |
Environment |
|
DC power | -48/60 VDC nominal, 350W, dual input |
Operating | 5 to 40°C (41 to 104°F) 5 to 85% relative humidity, noncondensing, subject to a maximum absolute humidity of 0.024 kg water/kg of dry air |
Short-term (96 consecutive hours) operating | -5 to 55°C (23 to 131°F) (at a maximum height of 1800 m) 5 to 90% relative humidity, noncondensing |
Non-operating | -40 to 70°C (-4 to 158°F) 10 to 95% relative humidity, noncondensing, subject to a maximum absolute humidity of 0.024 kg water/kg of dry air |
Tape streamer | Error-free operation at 0 to 40°C (32 to 104°F) |
Temperature variation | 30°C/hr maximum |
Elevation | Operating: -300 to +3000 m nonoperating: -300 to +12000 m |
Acoustic noise | Less than 60 dBA at a distance of 600 mm and a height of 1500 mm, measured at 25°C |
Earthquake | NEBS requirements for Earthquake Zone 4 |
Regulatory Compliance and Safety Specifications (meets or exceeds the following requirements) | |
Safety | UL 1950 3rd Edition, CSA C22.2 No. 950, TUV EN 60950, CB Scheme with Nordic deviations EMKO-TSE (74-SEC) 203, ZH1/618, GR-1089-CORE |
RFI/EMI | FCC Class A, EN 55022 Class A, EN 61000-3-2, GR-1089-CORE |
Immunity | EN 50082-1, GR-1089-CORE |
Certification | NEBS Bellcore SR-3850 1st edition Level 3 (mission critical), UL, cUL, CEMark, TUV Buart MarkM__UWJ_M__U |
Dimensions and Weights |
|
Height | 6.97 in. (17.70 cm) |
Width | 17.13 in. (43.50 cm) |
Depth | 19.53 in. (49.60 cm) |
Weight | 51.0 lb (23.18 kg) |
Enclosure | 19-, 23-, 24 in., 600 mm (requires mounting kit) |
Rack | 84 x 20 1/4 in. |
The ARU transmits critical, major, and minor alarms to the alarm center in the Network Operations Center (NOC).
The Failover controller or (A/B switch) implements the failover procedure. The controller is only required if you have a failover configuration. If using the failover controller, you need to connect the active and standby Cisco VSC2700 hosts via an Ethernet hub. For a brief overview of the failover process, see the section "System Redundancy."
The patch panel is used to connect site network E1/T1/V.35 lines to the Cisco VSC2700.
The serial port expander is required, in a failover configuration, to provide the additional asynchronous ports. For example, the Cisco VSC2700 hosts ship with two asynchronous ports built in. A typical failover configuration requires three asynchronous ports and a terminal (console) port.
The asynchronous ports are required for the following connections:
The Cisco Catalyst 8500 Series Multiservice Switch Routers (MSR) are modular Layer 2 and Layer 3 switch routers that provides wire-speed Ethernet routing and switching services. The systems are deployed as high-speed switch routers for campus or enterprise backbones.
The key features of the Catalyst 8500 Series MSR include the following:
You can use the following Cisco Catalyst 8500 Series MSR with the E1/T1 CES PAMs:
See the following sections for details.
These ATM switches are 5 Gbps modular switches designed for use in the workgroup or the campus, depending on the nature of the interfaces employed. The switches use a five-slot, modular chassis featuring the option of dual, fault-tolerant, load-sharing power supplies.
The Cisco switches offer the following functionality required for true ATM deployment:
All of this sophistication is hidden, however, by the true standards-based, plug-and-play capabilities of the Cisco switches, and advanced management functions allow for unprecedented levels of network visibility and control.
For details, refer to the following documents:
These publications are currently available online or on the Cisco Documentation CD-ROM. See the section, "If You Need More Information," and "Cisco Connection Online," for details.
For details, refer to the following documents:
These publications are currently available online or on the Cisco Documentation CD-ROM. See the section, "If You Need More Information," and "Cisco Connection Online," for details.
The Cisco LS1010s terminate the PRI T1/E1 interfaces, groom D channels, perform voice packetization, and create, maintain, and teardown 64 kb point-to-point connections.
For details, refer to the following documents:
These publications are currently available online or on the Cisco Documentation CD-ROM. See the section, "If You Need More Information," and "Cisco Connection Online," for details.
The Cisco Catalyst 5500 serves as the high-end modular switching platform. With a gigabit Ethernet-ready architecture that scales to more than 50 Gbps and throughput of tens of millions of packets or cells per second (pps), the Cisco Catalyst 5500 provides the scalability, flexibility, and redundancy required for building large, switched intranets and can be used in both wiring closet and backbone applications.
The Cisco Catalyst 5500 provides a seamless integration into existing Cisco Catalyst 8510s and Cisco LS1010s. With its support for hot-swappable modules, power supplies, and fans, the Cisco Catalyst 5500 delivers high availability for production networks. Dual redundant switching engines, power supplies, and a passive backplane design ensure full system redundancy for mission-critical environments.
For additional details, refer to the following documents:
These publications are currently available online or on the Cisco Documentation CD-ROM. See the section, "If You Need More Information," and "Cisco Connection Online," for details.
The Cisco OPT software requires the following software release levels:
This section briefly discusses some of the issues you need to take into consideration while designing and ordering your Cisco VSC2700 network solution.
The Cisco VSC2700 network solution includes these two main components:
To design your Cisco VSC2700 network solution, take the following steps:
The steps are described in the following sections.
To build a quality Cisco VSC2700 network solution, collect the following information:
Follow these steps to calculate the requirements for your network:
Step 1 List your PBX extensions in Table 12. Make sure that you account for reasonable network growth.
| PBX1 | PBX2 | PBX3 | Total | |
|---|---|---|---|---|
No of Extensions |
|
|
|
|
Step 2 Calculate voice traffic going out through each gateway from and to the adjacent PBX during the BH and add the information to Table 13.
| From/To | PBX1 | PBX2 | PBX3 | Total Traffic for each PBX/Gateway |
|---|---|---|---|---|
PBX1 | XXX |
|
|
|
PBX2 |
| XXX |
|
|
PBX3 |
|
| XXX |
|
Total Cisco VSC2700 Traffic |
|
|
|
|
Step 3 Calculate the number of PRI interfaces required for each gateway to handle incoming and outgoing traffic and add to Table 14. To calculate the required number of PRI interfaces for each PBX, divide the total traffic calculated in Table 13 by 30 for an E1 environment and by 23 for a T1 environment. Round off the interfaces and add them to the Required No. of Interfaces column in Table 14.
Step 4 Calculate the number of E1/T1 CES PAMs you need per gateway by dividing the required number of interfaces (in Table 14) by one of the following numbers:
| No. of PRI Interfaces (Total Traffic Divided by 30 for E1 Environment or 23 for T1 Environment) | Required No. of Interfaces | No. of E1/T1 CES PAMs per Gateway | |
|---|---|---|---|
PBX1 to Gateway |
|
|
|
PBX2 to Gateway |
|
|
|
PBX3 to Gateway |
|
|
|
Total |
|
|
|
Step 5 Choose and locate gateways.Your major considerations should be combined data and voice traffic volumes and required availability of the gateways.
Step 6 Calculate the number of Cisco VSC2700s needed to support expected traffic load using the following equation:
Number of Cisco VSC2700s = (Total Cisco VSC2700 Traffic)/(Average call duration)/(Cisco VSC2700 performance)
Step 7 Decide where to locate the Cisco VSC2700s and then assign gateways to Cisco VSC2700s. (Try to spread load evenly.)
Step 8 Decide the Cisco VSC2700 configuration (simplex or high availability) you will need for your solution. See the section "Cisco VSC2700 Virtual Switch Controller" for details.
To calculate the requirements for your Cisco VSC2700, complete the following steps and add the information to Table 15:
Step 1 Calculate the number of I/O interface cards (ITK-3) using the following guidelines:
Step 2 Select Cisco VSC2700 RAM memory size and add it to Table 15. For Cisco VSC2700 applications processing less than 30 call attempts per second with an average call hold time of 180 seconds, you can use the system with the memory option of 256 MB.
If the average hold time is greater than 180 seconds, use following formula to calculate additional RAM requirements:
Additional RAM = 35 x P x (t - 180)/1000
Where:
Step 3 Calculate the number of DS0s controlled by each Cisco VSC2700 by multiplying the total number of PRIs from the gateways (controlled by each Cisco 2700 to its PBX) multiplied by 30 (for E1 environments) or by 23 (for T1 environments). Add this information to Table 15.
| Item | Cisco VSC2700 1 | Cisco VSC2700 2 | Cisco VSC2700 3 |
|---|---|---|---|
Power supply |
|
|
|
Cisco VSC2700 RAM |
|
|
|
Simplex or high availability configuration |
|
|
|
Number of required E1/T1 I/O cards |
|
|
|
Number of calls during BH |
|
|
|
Required signaling protocols |
|
|
|
Number of DS0s |
|
|
|
Table 15 now contains the minimum requirements you need for the Cisco VSC2700 in your network solution.
You will need a secure NT server to run the Cisco VSC2700 Network Element Management System (NEMS). The NEMS server implements, maintains, and runs your Cisco VSC2700 network solution and is supplied by you, the customer. Cisco provides the NEMS application software as a part of Cisco VSC2700 network solution.
Table 16 lists the NEMS components.
| Cisco VSC2700 NEMS Components | Quantity | Provided By |
|---|---|---|
Hardware |
|
|
| 1 | Customer |
Ethernet Network Interface Card (NIC) | 1 | Customer |
Internal CD ROM | 1 | Customer |
SVGA video adapter (4 MB VRAM) | 1 | Customer |
56KB internal modem | 1 | Customer |
SVGA monitor (1024 x 768 minimum) | 1 | Customer |
Software |
|
|
Microsoft NT Server 4.0 running WWW services | 1 | Customer |
Microsoft Access 97 | 1 | Customer |
Cisco VSC2700 Configuration Tool (CT) software | 1 | Cisco |
Netscape Communicator (4.0.3) | 1 | Customer |
Hummingbird Exceed | 1 | Customer |
Cheyenne Innoculan NT (Server Edition) Antivirus protection | 1 | Customer |
Remotely Possible | 1 | Cisco |
Your final check items should include the following:
1. Make sure the number of calls per each Cisco VSC2700 does not exceed maximum Cisco VSC2700 performance of 30 calls per second (108,000 calls per hour).
2. Make sure the signaling protocols and features that you require are supported by the Cisco VSC2700 network solution.
3. Get approval from the necessary departments and groups.
4. Make sure you have collected all required logistical data, including the delivery time, shipping address, purchase orders, and contact information.
5. You are now ready to order and implement your Cisco VSC2700 network solution.
Once you have ordered your solution elements, you can then implement it following the guidelines in the section, "Implementing the Cisco VSC2700 Network Solution."
This section briefly describes a Cisco VSC2700 network solution implementation for an enterprise campus network that provides ATM data services and voice over circuit emulation point to point connections as shown in Figure 30.
In the above network:
Step 1 List the PBX extensions for this network in Table 17.
| PBX1 | PBX2 | PBX3 | Total | |
|---|---|---|---|---|
No of Extensions | 1000 | 2000 | 3000 | 6000 |
Step 2 Summarize the network voice traffic from and to the PBXs during BH in Table 18. Since PBX2 provides tandem services to the network, the traffic from PBX1 and PBX3 to the PSTN is calculated in increments from PBX1 to PBX2 and PBX3 to PBX2.
| From\To | PBX1 | PBX2 | PBX3 | Total Traffic for each PBX/Gateway |
|---|---|---|---|---|
PBX1 | XXX | 45 | 100 | 145 |
PBX2 | 45 | XXX | 150 | 195 |
PBX3 | 90 | 120 | XXX | 210 |
Total Cisco VSC2700 Traffic | -- | -- | -- | 650 |
Step 3 Calculate the required number of PRI interfaces from the PBXs to gateways, divide the total traffic (in Erlangs) calculated in Table 18 by the number of voice channels in the PRI link. Add this information to Table 19. There are 23 voice channels in PRI for T1. The last column shows the number of CES PAMs per gateway needed to carry the required voice traffic.
| Divided by 23 for (T1) Environment | Required Number of Interfaces | Number of E1/T1 CES PAMs per Gateway | |
|---|---|---|---|
PBX1-Gateway | 6.30 | 7 | 2 |
PBX2-Gateway | 8.48 | 9 | 3 |
PBX3-Gateway | 9.13 | 10 | 3 |
Total |
| 26 | 8 |
Step 4 Calculate the number of PRI interfaces and CES PAMs required between the network and the PSTN as shown in Table 20.
| Divided by 23 for (T1) environment | Required Number of Interfaces | Number of E1/T1 CES PAMs per gateway | |
|---|---|---|---|
Network to PSTN | 6.30 | 7 | 2 |
Step 5 Calculate the number of Cisco VSC2700s in the network (assuming an average call hold time of 180 seconds):
650/180/30 = 0.12
Therefore, this network solution requires only one Cisco VSC2700 running at 12% of its maximum capacity. As this solution uses only one Cisco VSC2700, locate it with any of gateways and choose a location convenient to service. The only other consideration in this is to maintain the lowest number of Soft PVCs for the tunneling signaling D channel. In this network solution, you might prefer to put your Cisco VSC2700 with the gateway passing the highest traffic, which is PBX2 in this solution.
Based on the calculation in Step 5, you need a high availability Cisco VSC2700 configuration.
Step 6 Calculate the following requirements for your Cisco VSC2700 and add the information to Table 21:
| Cisco VSC2700 Item | Description |
|---|---|
Power Supply | DC |
Cisco VSC2700 RAM size, MB | 256 |
Configuration | High Availability |
Number of required E1/T1 I/O cards | 4 |
Number of DS0s | 598 |
Step 7 Order your solution as listed in Table 22.
| Cisco Product Number | Quantity | Description |
|---|---|---|
VSC2701 | 1 | Virtual Switch Platform, Single System |
VSC2702 | 1 | Virtual Switch Platform, Dual System |
HOST-NETRA-T-DC | 2 | 4 Slots PCI; DC chassis |
VSC2700-E1 | 1 | Virtual Switch, E1 Interface Card Option |
VSC2700-T1 | 4 | Virtual Switch,T1 Interface Card Option |
VSC2700-IP | 1 | Virtual Switch, IP Interface Card Option |
VSC2700-E1T1-FO | 1 | Virtual Switch, E1/T1 failover card |
VSC2700-E1T1-FO= | 1 | Virtual Switch, E1/T1 failover card spare |
VSC2700-E1= | 1 | Virtual Switch, E1 Interface Card Spare |
VSC2700-T1= | 1 | Virtual Switch, T1 Interface Card Spare |
VSC2700-IP= | 1 | Virtual Switch, IP Interface Card Option |
AIS-VSC2700 | 1 | Advanced Installation Service |
TRN-VSC2700 | 5 | Cisco VSC2700 Customer Training, Priced per Person |
SW-VSC2700-V1.0 | 1 | Virtual Switch Software, V1.0 - Base, 200 DS0's Included |
SW-VSC2700-V1.0UP | 398 | Virtual Switch Software, V1.0 - Upgrade, 1 DS0 port |
MEM-256MB | 1 | System Memory Option per Server |
MEM-512MB | 1 | System Memory Option per Server |
MEM-128MB-UPGRADE= | 1 | Memory UPGRADE - 128 MB RAM per Server |
MEM-512MB-UPGRADE= | 1 | Memory UPGRADE - 512 MB RAM per Server |
Step 8 Continue with the guidelines in the following section, "Implementing the Cisco VSC2700 Network Solution."
Step 1 Read the previous section, "Designing the Cisco VSC2700 Network Solution" if you have already not done so.
Step 2 Collect the hardware to build your network solution. Note that this list is a guide only. Depending on your network design you could require additional hardware.
Step 3 Connect the hardware. See the section "Hardware Connections" for details.
Step 4 Configure and deploy the configuration files on the devices in this order:
(a) Cisco VSC2700
(b) Cisco Catalyst 8000 Series MSR gateways
Step 5 Make sure all the devices can talk to each other by pinging the gateways from the Cisco VSC2700.
This section provides an overview of the recommended hardware connection sequence. For details, refer to the appropriate hardware installation guide.
 | TimeSaver Make sure you have the hardware installation guides for all the devices you are connecting in your network. |
Step 1 Wire up the Cisco VSC2700 in this sequence:
(a) If using dedicated DC power, connect the power supply to the Cisco VSC2700.
(b) Install the expansion slot between the Cisco VSC2700 and the failover box.
(c) Connect the Cisco VSC2700 to the Fast Ethernet hub.
(d) Connect the Fast Ethernet hub to your LAN.
(e) Connect a console terminal to the Cisco VSC2700 hosts using an EIA/TIA-232 cable.
Step 2 Connect the Cisco Catalyst 8000 Series MSR gateways to the ATM network.
Step 3 Connect the Cisco Catalyst 8000 Series MSR gateways to the PBXs.
Step 4 Connect the Cisco VSC2700 to the Cisco Catalyst 8000 Series MSR gateways using the T1/E1 CES PAMs ports.
Step 1 Collect the following information:
Step 2 Install the software on the Cisco VSC2700.
Step 3 Determine which ports on the PBXs will connect to the Cisco Catalyst 8500 Series MSR gateways.
 | Caution Always use the Cisco VSC2700 configuration tool to create, modify, manage, and deploy your configuration files on the Cisco VSC2700. We do not recommend modifying the configuration files manually on the Cisco VSC2700. |
Step 4 Build the Cisco VSC2700 .dat files using the Configuration Tool and then download the .dat files to the Cisco VSC2700. Refer to the Cisco Telephony Controller Software Release and Configuration Tool Guide publication for details.
Step 5 Use the dial plan provisioning (DPP) tool to create the dial plan and then activate the dialplan using MML. Refer to the Cisco Telephony Controller Software Release and Configuration Tool Guide publication for details.
Step 6 Enable SGCP on the Catalyst 8500 Series MSR gateways. Refer to the appropriate configuration guides for details. See section "ATM Switches (Trunking Gateways)" for a list of publications.
Refer to the documentation that shipped with a particular component for configuration information.
You have 24-hour support for your Cisco VSC2700 network solution via Cisco's Technical Assistance Center (TACs). There are four TACs worldwide. To initiate a case, contact the closest TAC and tell them your problem. You will be issued a case number that you can check via the phone or the web. Check the following URL for the most current list of TAC telephone numbers:
Cisco TAC also offers support in several languages during business hours and English after business hours. You can send e-mail to the e-mail addresses listed in Table 23 and receive answers in the language indicated in Table 23.
| Language | E-Mail Address |
|---|---|
English/Spanish | tac@cisco.com |
Hangul (Korean) | korea-tac@cisco.com |
Hanzi (Chinese) | chinese-tac@cisco.com |
Kanji (Japanese) | japan-tac@cisco.com |
Thai | thai-tac@cisco.com |
You can also initiate your case online via the Internet at www.cisco.com. Outside these locations, contact the Cisco regional sales office nearest you, or contact your local authorized Cisco distributor.
The hard copy of this publication is updated at major releases only and does not always contain the latest material for enhancements occurring between major releases. You are shipped separate release notes or configuration notes for spares, hardware, and software enhancements occurring between major releases.
The online copy of this guide is always up-to-date and integrates the latest enhancements to the product. You can access the current online copy of this guide on the World Wide Web at http://www.cisco.com, http://www-china.cisco.com, or http://www-europe.cisco.com.
1. Configuring the VSC2700---Ships on the documentation CD-ROM with the Cisco VSC2700 and the most current version is available on the Cisco web site.
2. Configuring SGCP on the Switch---Ships on the documentation CD-ROM with the Cisco VSC2700 and the most current version is available on the Cisco web site.
3. Configuration Tool Guide---Ships on the documentation CD-ROM with the Cisco VSC2700 and the most current version is available on the Cisco web site.
4. Dial Plan Provisioning---Ships on the documentation CD-ROM with the Cisco VSC2700 and the most current version is available on the Cisco web site.
5. Software Operations and Maintenance---Ships on the documentation CD-ROM with the Cisco VSC2700 and the most current version is available on the Cisco web site.
6. Release Notes---Available through your Cisco representative.
The Cisco IOS software running on your router contains extensive features and functionality. The effective use of many of these features is easier if you have more information. For additional information on configuring and maintaining a Cisco VSC2700, the following documentation resources are available:
Cisco Connection Online (CCO) is Cisco Systems' primary, real-time support channel. Maintenance customers and partners can self-register on CCO to obtain additional information and services.
Available 24 hours a day, 7 days a week, CCO provides a wealth of standard and value-added services to Cisco's customers and business partners. CCO services include product information, product documentation, software updates, release notes, technical tips, the Bug Navigator, configuration notes, brochures, descriptions of service offerings, and download access to public and authorized files.
CCO serves a wide variety of users through two interfaces that are updated and enhanced simultaneously: a character-based version and a multimedia version that resides on the World Wide Web (WWW). The character-based CCO supports Zmodem, Kermit, Xmodem, FTP, and Internet e-mail, and it is excellent for quick access to information over lower bandwidths. The WWW version of CCO provides richly formatted documents with photographs, figures, graphics, and video, as well as hyperlinks to related information.
You can access CCO in the following ways:
For a copy of CCO's Frequently Asked Questions (FAQ), contact cco-help@cisco.com. For additional information, contact cco-team@cisco.com.
Posted: Fri Apr 23 13:01:41 PDT 1999
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