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This chapter introduces common MGX 8850 switch topologies, provides an overview of the configuration process, and presents guidelines for collecting the information you will need to complete the configuration.
Release 2.0 of the MGX 8850 supports the following topologies:
The following sections introduce these topologies.
Figure 1-1 shows the MGX 8850 operating in a core switch topology.
In the core switch topology, the MGX 8850 works with other ATM switches to transfer broadband ATM traffic from one ATM edge device to another. The core serves as a freeway and the edge devices operate as freeway on ramps. The core and edge devices are typically placed in different locations.
The MGX 8850 supports trunks operating at DS3, E3, OC-3, OC-12, and OC-48 speeds. Typically, core nodes communicate with multiple edge nodes over relatively slower broadband trunks such as DS3, E3, and OC-3 trunks. The core node communicates with other core nodes using relatively faster links such as OC-12 and OC-48 trunks.
Figure 1-2 shows the MGX 8850 operating in a multiservice edge aggregation topology.
In the multiservice edge aggregation topology, the MGX 8850 is colocated with other ATM equipment and communicates with one or more core switches at remote locations. The MGX 8850 aggregates the traffic from multiple local ATM devices and packages it for high-speed communications over the core.
Typically, multiservice edge nodes communicate with colocated ATM devices over relatively slower broadband trunks such as DS3 and E3 trunks. The multiservice edge node communicates with core nodes using relatively faster links such as OC-3, OC-12, and OC-48 trunks.
Figure 1-3 shows the MGX 8850 operating in a Digital Subscriber Link (DSL) edge aggregation topology.
In the DSL edge aggregation topology, the MGX 8850 is colocated with Digital Subscriber Line Access Multiplexers (DSLAMs) and communicates with one or more core switches at remote locations. The MGX 8850 aggregates the DSL traffic from multiple DSLAMs and packages it for high-speed communications over the core.
Typically, DSL edge nodes communicate with colocated DSLAMs over relatively slower broadband trunks such as DS3 and E3 trunks. The DSL edge node communicates with core nodes using relatively faster links such as OC-3, OC-12, and OC-48 trunks.
Switch configuration is easier if you are familiar with the overall configuration process. To configure and start up the MGX 8850 Release 2.0, you need to do some or all of the following:
"Configuring General Switch Features," describes how to set up general switch features such as the date, the PNNI controller, and network management. You need to follow the procedures in this chapter to prepare your switch for general operation.
"Configuring ATM Lines and Trunks," describes how to configure and activate ATM links that connect this switch to other ATM devices.
"Address Selection, Call Routing, and WAN Switching Using the PNNI Protocol," introduces Private Network-to-Network Interface (PNNI) and describes how to design your network to use PNNI. PNNI call routing makes switch configuration much easier, but it is optional. If you do not enable PNNI call routing, you must manually configure static routes to other devices.
To successfully configure the MGX 8850, you must collect information about the other devices to which it will connect. You need to know the line speeds and protocols used on the trunks that connect to the switch. You also need to know addressing plan for the network in which the switch is installed. This information can be grouped into the following categories:
The following sections introduced these types of data and provide guidelines for collecting the data you need for switch configuration.
During configuration, you will need to enter general configuration data that describes the switch and how it will be used in the network. This data includes:
The following sections describe this information in more detail.
Each switch must have its own unique name within the ATM network. If you are adding a switch to a network, find out if the network administrator has established switch naming conventions, and find out which names have already been used. It is a good practice to name switches according to location, as this conveys both the switch identity and its location.
A network addressing plan is critical for successful operation of the MGX 8850 in an ATM network. The Private Network-to-Network Interface (PNNI) protocol uses structured network addresses to logically group network devices and determine routes between devices.
PNNI network addressing is described in "Address Selection, Call Routing, and WAN Switching Using the PNNI Protocol."
The MGX 8850 supports dynamic and static addresses on UNI ports. The configuration for static and dynamic addressing is described in "Configuring UNI Port Addressing" in "Configuring ATM Lines and Trunks."
In most cases, you will want to allow more than one administrator to manage the switch. The MGX 8850 supports multiple administrators and several different administration levels. As part of the planning process, you might want to identify who will be managing the switch and at what level. You can learn more about managing administrators by reading "Configuring Administrator Access" in "Configuring General Switch Features."
Clock synchronization in an ATM network is very important. The MGX 8850 can use an internal clock source or an external clock source, and it can be configured to switch clock sources when the primary clock source fails. Configuration will be easier if you plan your clock synchronization before you start. For information on MGX 8850 clock source operation, see "Managing Network Clock Sources" in "Configuring General Switch Features."
You can use the following tools to manage the Cisco MGX 8850:
The Command Line Interface (CLI) tool that comes with the switch is the least expensive option. To use the other tools, you must purchase Cisco WAN Manager (CWM) or a Simple Network Management Protocol (SNMP) manager. The MGX 8850 comes with an SNMP agent for use with an SNMP manager.
The advantage to using Cisco WAN Manager or an SNMP manager is that you can use one program to simultaneously manage multiple devices. Cisco WAN Manager is also the only management tool that can configure Service Class Templates (SCTs), which are described in "Configuring General Switch Features.". Most installations require at least one Cisco WAN Manager workstation to complete the switch configuration.
This book describes how to configure and monitor the switch using the CLI tool. For instructions on managing the switch with Cisco WAN Manager, refer to the following books:
For information on managing the switch with an SNMP manager, refer to the following:
When configuring lines and trunks that connect the switch to other devices, you need to collect the following types of data:
The MGX 8850 supports many of the most common ATM configuration parameters. To successfully configure lines and trunks, you need to be sure that the configuration settings used on the switch match the configuration settings used at the other end of the line or trunk. In some cases, you may find that options you want to use at one end of the trunk aren't supported at the other end. In these situations, you need to change your configuration plan to use settings that are supported at both ends. Line and trunk configuration is described in "Configuring ATM Lines and Trunks."
Posted: Mon Aug 7 08:42:25 PDT 2000
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