The MPLS WG Archive

["David Allan" <dallan@nortelnetworks.com>]

LSR self test is a milestone in this charter, yet I've seen NO discussion of
this on the list other than Loa's brief email soliciting comment back in
July. I understand that normally some interest beyond a few friends hands is
usually a pre-requisite to adopting work......

......So I'll ask a simple technical question to try and spark some
discussion after the fact. If I have an LSR popping the stack in error, I
suspect this will not be detected by an LSR testing itself. As PHP is
considered acceptable behavior, the downstream LSR would NOT observe that
the PING packet on which TTL expired did not arrive as a labelled packet, it
simply looks at the FEC TLV and goes ***OK, it looks reasonable***. There is
no guarantee that the LSR downstream of the defective pop would catch this
either via its use of LSR self test mechanisms as the path into the
defective LSR is assuredly different than that of real traffic.

IMHO if my LSRs are generating a ping transaction for every ILM entry in my
network (which is a s***load of a lot of pings no matter how slowly I run
this stuff), am I really accomplishing anything if discontinuties in the
label switched path cannot be detected by this mechanism? 

cheers
Dave