Sense code 087D0001 received with session activation failure

Problem statement

Session activation failed with the sense code 087D0001.

Common symptoms

An attempt to establish a session failed and the sense code 087D0001 (routing exhausted) was returned. Messages IST894 and IST895 indicate that one of the adjacent SSCPs tried is ISTAPNCP with a failure sense code of 087F0001 (resubmit requested for a request that was already resubmitted).

Probable cause

Possibly one of the following conditions:

If messages IST894I and IST895I are issued, one of the adjacent SSCPs was ISTAPNCP with a failure sense code of 087F0001. This indicates that VTAM® knows which node owns the LU but is not able to route a directed search to that node to verify the availability of the LU.
There is no SSCP-SSCP session.
The half-session control block (HSCB) count is too low in the NCP to handle the number of sessions. A possible solution to this problem is to code a larger value on the ADDSESS keyword of the BUILD definition statement and regen.
Both sides are using the same SSCP name.

User response

Verify that a valid search path exists. This includes CP-CP sessions, a subarea path, or both. One possible source of the problem is the absence of a CP-CP session between two nodes that share an active link that is CP-CP capable. If this situation occurs, take one of the following actions:

Reactivate the CP-CP session.
Deactivate the link, and reactivate it as a link that is not CP-CP capable. This notifies topology and routing services that the link is no longer available for use in directed search routing.