Overriding LNS Out-of-Resource Result Codes 4 and 5

When the number of L2TP sessions reaches the configured maximum value, the LNS sends an out-of-resource result code (4 or 5) in a CDN (Call-Disconnect-Notify) message to the LAC. This signals the LAC to fail over to another LNS that has the resources for more sessions.

Some third-party LAC implementations fail over only when they receive result code 2 sent in the CDN from the LNS. You can override result codes 4 and 5 with result code 2 on the LNS to enable such routers to fail over to another LNS. These codes have the following meanings:

2—Call disconnected for the reason indicated in error code
4—Call failed due to lack of appropriate facilities being available (temporary condition)
5—Call failed due to lack of appropriate facilities being available (permanent condition)

The following sections describe how to override the result codes and how to display the current code values.

Overriding the Result Codes

You can override the out-of-resource result codes 4 and 5 by issuing the session-out-of-resource-result-code-override command on the LNS.

To override result codes 4 and 5:



host1:boston(config-l2tp-dest-profile-host)#session-out-of-resource-result-code-override

Displaying the Current Override Setting

You can view the current override setting for the LNS result codes in the L2TP destination profile.

To display the current override setting:

ERX(config)#show l2tp destination profile boston
L2TP destination profile boston
Configuration
  Destination address
    Transport ipUdp
    Virtual router default
    Peer address 10.10.76.12
Statistics
  Destination profile current session count is 0
Host profile attributes
  Remote host is LAC
    Configuration
      Tunnel password is TunnelPass
      Local host name is LNS
      Local ip address is 46.1.1.2
      Disconnect-cause avp is enabled
      Tunnels are single-shot
      Override out-of-resource-result-code is enabled
    Statistics
      Current session count is 0
1 L2TP host profile found