IBM SC30-3681-08 XTP Backup Peer Function, Searching for a Remote DTE, XTP configadd local-dte

Using XTP

or ª*º. The special case of a DTE address of ª*º represents any DTE address, even a null address. The null address is useful for handling incoming calls with no calling address in the X.25 Call Request packet.

Use of the ª*º wildcard increases the chances for adding a local or a remote DTE address that con¯icts with an existing address. Theadd local-dteand add remote-dtecommands are enhanced to provide the con¯icting address when the user attempts to add a DTE address that con¯icts with an existing address.

Example: xtp config> add local-dte

Interface number [0]? 1

DTE address [ ] 123456

DTE address [ ]?

XTP config>add local-dte

Interface number [0]?1

DTE address [ ]?1*

DTE address conflicts with existing DTE address 123456

XTP Backup Peer Function

The Backup Peer Function allows the association of multiple peer routers with a remote DTE. The user speci®es a list of peer routers associated with a remote DTE.

Example:

XTP config>add rem

DTE address [ ]?123456

Peer router©s internal IP Address [0.0.0.0]?10.0.0.2

Peer router©s internal IP Address [0.0.0.0]?10.0.0.4

Peer router©s internal IP Address [0.0.0.0]?11.0.0.1

Peer router©s internal IP Address [0.0.0.0]?

When an incoming call for the remote DTE is received, a connection is attempted through each router in the list in the same order that they appear for the remote DTE.

Searching for a Remote DTE

When a DTE initiates a call for a remote DTE, both DTE addresses are inspected to determine if they are acceptable for X.25 transport. If they are acceptable, the X.25 Transport protocol forwarder determines through which peer router to attempt to complete the call. It starts with the ®rst router in the remote DTE's list of peer routers in its search. The ®rst condition that must be met is an active TCP connection to the peer router. If there is not an active TCP connection to the peer, the next router in the list is checked. When an active TCP connection is found, an attempt is made to complete the call. The Connection Request Timer is started to time the call connection process.

The remote DTE search is terminated by one of the following events:

vSuccessful completion of the call through the peer router

This completes call setup processing and ends the search for the remote DTE.

vRejection of the call by the peer router

This causes the search for the remote DTE to proceed to the next router in the peer router list.

vExpiration of the Connection Request Timer

364MRS V3.2 Software User's Guide