Making Frame Relay Connections

Making Frame Relay Connections

This section outlines how to establish Frame Relay service by setting up a universal frame module (UFM) or a Frame Relay module (FRM). The information includes details for T1, E1, HSSI, V.35, and X.25 interfaces. Detailed descriptions of the Frame Relay commands appear in the Cisco WAN Switching Command Reference. Specific cabling requirements for the UFI back cards on the UFM-U appear in the UFM-U description in the Cisco IGX 8400 Series Reference.

Maximum Connections Per Port with Signalling Protocols

For any Frame Relay card set that has a maximum frame length of 4510 bytes, the type of signaling protocol you can (optionally) specify with cnffrport results in a limit on the number of connections per physical or logical port. The maximum number of connections per port for each protocol is:

For Annex A: 899

For Annex D: 899

For StrataLMI: 562

Neither addcon nor cnffrport prevents you from adding more than the maximum number of connections on a port. (You might, for example, use cnffrport to specify an LMI when too many connections for that particular LMI already exist.) If the number of connections is exceeded for a particular LMI, the LMI does not work on the port, the full status messages that result are discarded, and LMI timeouts occur on the port. A port failure results and also subsequently leads to a-bit failures in other segments of the connection path.

Setting Up Frame Relay on a UFM

Channelized and unchannelized versions of the UFM card sets exit. The channelized front cards UFM-4C and UFM-8C operate with T1 and E1 interfaces, and the unchannelized front card UFM-U operates with V.35, X.21, and HSSI interfaces.

The back cards have the following terminations:

The UFI-8T1-DB-15 has 8, female, subminiature DB-15s.

The UFI-8E1-DB-15 has 8, female, subminiature DB-15s.

The UFI-8E1-BNC has 16 BNC connectors, 1 for each direction.

The UFI-12V.35 has 6 low-force helix (LFH) connectors with 2 ports per connector.

The UFI-12X.21 has 6 low-force helix (LFH) connectors with 2 ports per connector.

The UFI-4HSSI has 4 connectors.

If the installation includes Y-cable redundancy, first read the section “Y-Cable Redundancy on the UFMs.”

Y-Cable Redundancy on the UFMs

Redundancy for a Frame Relay port is possible with a second card set and the appropriate Y-cable. The card redundancy kit for UFM contains a second UFM/UFI card set and Y-cables to interconnect the ports on the two back cards. The forthcoming section titled “Setting Up Frame Relay Ports and Connections (UFM)” includes the step for configuring Y-cable redundancy.

Refer to the cabling description in the UFM-U section of the Cisco IGX 8400 Series Reference for descriptions and part numbers of all cables for unchannelized UFMs.

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Cisco Systems IGX 8400 Series manual Making Frame Relay Connections, Maximum Connections Per Port with Signalling Protocols