Subject: Proposed Update to TRS Architecture

From: "Roy Brabson (254-7332 (T/L 444))" <[email-masked]>
Date: Thu, 6 Oct 94 14:19:30 EDT

> One way to solve this problem, which reduces the number of times these
> CP-CP reachability checks need to be done to the bare minimum, is to add the
> following capability to NNs:
>
> Whenever a local TG to an NN goes down, the local NN checks whether a route
> using COS CPSVCMG can still be built to that partner NN.  If so, send a TDU
> inoping that TG only.  If a route can't be built, send a TDU inoping the TG
> and marking the partner NN as inconsistent (odd RSN).  Now all NNs are clued
> in simultaneously, as soon as the disconnection happens, not to use the NN
> that disconnected from the network, while only one check needs to be done.
> This solves the problem with a minimal # of these CP-CP session reachability
> checks being done.

Please be *very* careful about having nodes sending a TDU describing
other nodes.  Unless you are 100% sure you cannot reach the node, you
may cause a TDU war to start.  With all the race conditions involved
with TRS and TDUs, a TDU war is more likely than it may first appear.

Roy Brabson