nanog mailing list archives
Re: Possible explanations for a large hop in latency
From: Sam Stickland <sam_mailinglists () spacething org>
Date: Wed, 02 Jul 2008 01:07:23 +0100
Even if they are decrementing TTL inside of their MPLS core, the TTL expired message still has to traverse the entire MPLS LSP (tunnel), so the latency reported for each "hop" is in fact the latency of the last hop in the MPLS network. Always.
Sam Robert Richardson wrote:
They probably don't propagate TTL w/in their MPLS core. Depending on how they have MPLS implemented, you may only see 2 hops on the network; the ingress and egress routers. If the ingress router was in NYC and the egress in Seattle, you could understandably expect a large jump in RTT. Not an ATT customer but do know other providers run their MPLS core's this way... -Robert On Thu, Jun 26, 2008 at 6:09 PM, John T. Yocum <john () fluidhosting com> wrote:
Current thread:
- Re: Possible explanations for a large hop in latency Sam Stickland (Jul 01)
- Re: Possible explanations for a large hop in latency Bruce Pinsky (Jul 01)