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[EFM] RE: [EFM-OAM] Performance monitoring, installation, trouble shoot ing.


It looks like there has been an epiphany in EFM thanks to the knowledge base
of a few of the individuals that have experience of delivering multiple
services over the last mile. I don't include myself in that category as I
have never been a service provider and never been in the POTS business.

Servicing 32 customers with time critical data e.g. T1 or POTS (leave aside
video for now), requires a scalable TDM like mechanism. Multiple request
messages could help with this, but there is still only one pipe to the user.
The real solution is multiple pipes to the user, fat ones for data / video
and thin deterministic ones for voice. The current proposals do not support
that (and therefore could be said to fail the broad market criterion).

Best regards


-----Original Message-----
[]On Behalf Of
Sent: 24 January 2002 01:45
To: Chou, Joey
Cc: Geoff Thompson; bob.barrett@xxxxxxxxxxxxxxx; mattsquire@xxxxxxx;;
Subject: RE: [EFM-OAM] Performance monitoring, installation, trouble
shoot ing.


As you said:

> 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 data packets.

Assuming that the typical speed of the EFM link is going to be very high,
this blocking effect is not really an issue, as it can be solved with good
queue management. That's an implementation issue. For low speed links, this
is a serious problem, because it takes a long time to transmit a big frame.
The Frame Relay Forum took specific measures to avoid this situation; for
examplo, big frames may be fragmented before transmission. It's better to
avoid fragmentation, though, as it's a complex implementation that presents
its own set of issues to be solved.

That said, it's important to state that this is not enough to solve all
issues related to the support of TDM emulation services over EFM. Speed is
good, and may help a lot by avoiding the need for complex mechanisms such
as fragmentation, but there are other issues to watch out, specially in the
case of the P2MP implementation.

Carlos Ribeiro
CTBC Telecom