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In addition, the SNMP (Simple Network Management Protocol) Service Agent module in CWM provides automated, flow-through interfaces to higher-level Service Management applications (for example, OSS (Operations Support Systems) at a Service Provider's Network Management Center, for automated provisioning and fault management).
The key strengths of CWM are scaleability (some of the world's largest broadband networks having in excess of 200,000 PVCs are managed using CWM) and performance data collection (in excess of a million statistics/collection agent/hour, an industry-leading figure). CWM also relies on a distributed management architecture, in which the network is the master source of information, which leads to advantages in terms of overall reliability and robustness with respect to center-weighted NMS-focused architectures used by competitors. Multiple CWM's can manage the network and maintain an identical view of the network(s). This enables specific CWM instances to manage management applications for networks. For example, Connection Management can be executed on one CWM workstation, Statistics Collection can be executed from a second CWM workstation, and Fault Management can be executed from a third CWM workstation. CWM also implements RTM (Robust Trap Mechanism), which consists of extensions on top of the underlying SNMP mechanism (while still remaining in the IETF-standards-based SNMP framework) to address inherent unreliable delivery problems with standard SNMP traps which are based on UDP (User Datagram Protocol). RTM provides a mechanism for robust, reliable exchange of standard UDP-based trap (event) information, which is an important differentiation in mission-critical environments.
In summary, WAN management of IGX 8400, BPX 8600, MGX 8220, MGX 8800, IPX multiservice networks is comprehensively addressed by the CWM product line, which provides advanced operations, maintenance, and management capabilities (including topology, configuration, connection, fault, and performance management).
Figure 1-1 is a sample network of Cisco switches and routers being managed by CWM.
The primary point of integration of provisioning and fault management is through the SNMP Service Agent, which serves as an integration point to Service Management Layer (SML) functionality. Service Management refers to the functionality related to managing specific services, such as PVCs' port provisioning. The Service Agent provides an SNMP interface to the end-to-end connection management for the following:
The Service Agent supports the following card types:
The Service Agent provides provisioning interface for Frame Relay, ATM, CESM, FRASM, and Data/Voice ports for the following card types:
The Service Agent enables fault management capabilities based on SNMP traps, and enhances this trap interface with Robust Trap Mechanism (RTM). RTM guarantees delivery of all traps from an element to external WAN-agent. This allows retrieval of lost traps. This facility enables external OSS's to have real time status view of the network. Cisco has plans to enable SNMP interface to TMN Q3 interface.
In addition to provisioning and fault management, the Service Agent provides access to node configuration information and other network information.
The physical link between the CWM workstation and the SNMP Manager workstation must be an Ethernet LAN. A typical connection over an Ethernet network is shown in Figure 1-2.
Figure 1-2 shows the software and database modules involved in a BPX 8600, MGX 8220,
MGX 8800, and IPX network being monitored by a SNMP manager. The Service Agent software resides in the CWM workstation along side the CWM software with both operating under the Solaris 2.6 operating system.
The CWM software monitors and manages the BPX 8600/MGX 8220/MGX 8800/IPX network through its proprietary hardware and software connection to one of the BPX 8600, MGX 8800, or IPX nodes on the network. CWM maintains a current database of the network using the Informix database software system.
The Service Agent software consists of an SNMP engine and the Service Agent itself. Both programs, once started, are transparent to the CWM operator and operate entirely in the background. The Service Agent maintains a current Management Information Base (MIB) of the
BPX 8600/MGX 8220/MGX 8800/IPX network using the data in the Informix database and which can be interrogated by the SNMP Manager. Statistics are obtained by the Service Agent directly from CWM through the CWM Realtime Counters feature. The Service Agent also maintains a small database which contains local configuration data.
The link between the CWM workstation and the SNMP Manager employs the Internet Protocol (IP) using the User Datagram Protocol (UDP) feature over an Ethernet LAN.
When installed network equipment does not support SNMP, there are two ways to add SNMP capability:
1. Integral SNMP, which requires retrofitting each network element to be managed. Software, and in most cases hardware, must be upgraded.
2. A Service Agent, which provides SNMP capability for multiple network elements. The Service Agent translates between SNMP and the network elements' management protocol(s).
Installing a Service Agent is the preferable solution, not only because it eliminates the arduous task of retrofitting installed equipment, but because it simplifies future upgrades. SNMP is an evolving protocol, and periodic enhancements are to be expected. When a Service Agent is employed, a software download of the Service Agent is all that is required to upgrade the SNMP software. Without a Service Agent, each SNMP-managed device must be individually upgraded.
The SNMP Agent configuration file (SNMPAgent.conf) is located in the /usr/users/svplus/config directory.
The UDP port used for SNMP Requests can be configured in this file.
Syntax: | TRANSPORT | SPECIAL SNMP |
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| OVER UDP SOCKET |
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| AT PORT 8161 |
Port 8161 is the default UDP port. It may be changed to match your system's requirements.
After changing the UDP port, you must send a SIGHUP to the SNMP Agent process to force it to read the configuration file again.
The SNMP Service Agent configuration file (SNMPProxy.conf) is located in the /usr/users/svplus/config directory.
The SNMP community strings are configured in this file. As community strings are used as an index in the Node and Event MIBs, RtmProxy does not require this configuration file. Only ConnProxy (connGroup MIB), PortProxy (portGroup MIB), and DasProxy (insDAS MIB) use these community strings for authentication.
Syntax: | GET_COMMUNITY | public |
| SET_COMMUNITY | private |
The Service Agent defaults are GET = public and SET = private.
The Service Agent reads the configuration file only at start-up. When you make changes to the configuration file, you must restart the Service Agent (that is, ConnProxy, DasProxy, and PortProxy) to obtain the new configuration information.
This document uses HP OpenView SNMP command line utilities for accessing the CWM Service Agent. The format of the HP OpenView SNMP command line utilities is as follows:
1. snmpget -c <community-string> -p <snmp-agent-port-number> <agent-hostname> <ObjectId> [<ObjectId>...]
2. snmpwalk -c <community-string> -p <snmp-agent-port-number> <agent-hostname> <ObjectId>
3. snmpset -c <community-string> -p <snmp-agent-port-number> <agent-hostname> <ObjectId> <Object-type> <value>
where, <Object-type> can be one of the following: integer, integer32, unsigned32, octetstring, octetstringhex, octetstringoctal, octetstringascii, objectidentifier, null, ipaddress, counter, counter32, counter64, gauge, gauge32, timeticks, opague, opaguehex, opagueoctal, opagueascii.
CWM uses the following format for encoding variable length strings into Object IDs (OIDs). The string "axis10" is encoded to: 6.97.120.105.115.49.48 where:
6 = the length of the string (six characters)
97 = "a"
120 = "x"
105 = "i"
115 = "s"
49 = "1"
48 = "0"
Posted: Tue Apr 6 09:57:59 PDT 1999
Copyright 1989-1999©Cisco Systems Inc.