[EFM] RE: [EFM-OAM] Performance monitoring, installation, trouble shooting.
Geoff and Carlos,
End-to-end QoS is required, if the IP networks were to support the mix of
real-time (e.g. voice, video) and non-real-time(e.g. data) applications. It
is true that several mechanisms, such as Diffserv, RSVP, MPLS, have been
designed in the upper layers to support QoS. However, the true end-to-end
QoS will not happen until QoS is supported in every network segment along
the path. 802.1D user_priority uses 3 bits in the 802.1Q VLAN tag to define
8 types of traffic riding in the Ethernet frame.
I thought there should be a need for an OAM requirement to support 802.1D
user_priority bits to prevent voice packets from blocking by huge Ethernet
From: carlosal@xxxxxxxxxxxxxxxxxx [mailto:carlosal@xxxxxxxxxxxxxxxxxx]
Sent: Monday, January 21, 2002 11:20 AM
To: Geoff Thompson
Cc: bob.barrett@xxxxxxxxxxxxxxx; mattsquire@xxxxxxx;
Subject: RE: [EFM-OAM] Performance monitoring, installation, trouble
Thanks for your comments. Just to make my point clear: I was not
requesting, or even defending, that EFM should explicitly support QoS, or
synchronous services, or anything similar. I was concerned about the way we
are discussing requirements. In my opinion, we can't even start discussing
specific technical requirements if we dont have a thorough understanding of
the service requirements. I've been insisting on this position for a long
time, for one very important reason: it's fundamental to understand the
application before we start discussing technical details.
I'm not the only carrier representative tracking these email reflectors.
While as a group we diverge on a lot of things (for example: maximum loop
lengths), we (mostly) agree on other things, namely in the fact that we
expect EFM to provide a common framework for the access network, supporting
not only data services, but also voice and video. There are many different
ways to support these applications, ranging from explicit support to the
assumption that the upper layers (read IP) will take care of this.
The actual requirements for OAM depend on two questions, both still pending
Q1. what are services directly supported by EFM;
Q2. what is the typical business model for EFM deployment.
The answers for these questions are by no means absolute: every SP will
give you a different answer. Even then, it's possible to understand the
main applications we (service providers) foresee for EFM, and then proceed
with the technical requirements.
Thanks again, and best regards.