Albert - From: Albert Fu (BLOOMBERG/ 120 PARK) <af...@bloomberg.net> Sent: Tuesday, October 23, 2018 8:45 AM To: rtg-bfd@ietf.org; Les Ginsberg (ginsberg) <ginsb...@cisco.com> Subject: RE: BFD WG adoption for draft-haas-bfd-large-packets
Hi Les, Given that it takes relative lengthy time to troubleshoot the MTU issue, and the associated impact on customer traffic, it is important to have a reliable and fast mechanism to detect the issue. [Les:] This is one of the points where we are not in full agreement. I agree you need an easy and reliable way to detect the problem when it occurs. However, I disagree that you need to do this “fast” – when fast is defined as sub-second. You have something that we know only occurs during some maintenance event – which is planned and only occurs “once/day,week”. Checking for this even once/second is overly aggressive. If it came for free, then no reason not to do so. But as this discussion has shown, there are costs/risks. For example, if you were using IS-IS and you detected this within the default adjacency hold time (30 seconds on p2p circuits) – would that be too slow for you? If so, please explain why this is too slow. I think the primary issue here is ease of use and reliability. Whether detection time is one second or one minute seems relatively unimportant. Do you disagree? Les
