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RE: [EFM] TDM circuit emulation




Bob,

The real problem is not how to do the T1/E1 emulation over broadband 
Ethernet.  The issue is what does the service provider do with the rest of 
the bandwidth that makes it economically realistic?  In most cases they are 
looking to provide multiple services over that bandwidth.  The question 
that pops up is what is the security of the T1/E1 emulation over that 
bandwidth when the service provider needs to put more than one customer in 
that bandwidth?  Your suggestion of using a true "out of band" TDM "like" 
functionality would tend to be the simplest way to provide the accepted 
security of a T1/E1 type of service.  Otherwise the T1/E1 emulation would 
be intermingled with multiple customers' traffic and require very complex 
security measures.  I think that the paradigm of intermingled traffic is 
what is being seen in the concerns over security.  Somehow we have to get 
out of that "all or nothing" type of thinking.

Thank you,
Roy Bynum

At 02:33 PM 12/11/2001 +0000, Bob Barrett wrote:
>Roy,
>
>I see this as full T1/E1 pipes primarily, used for voice traffic and
>possibly RAS PRI. DSO granularity is unlikely to be required on fiber. The
>full pipe can carry fractional simply, and I don't think we will be worried
>about saving 1M here or there, not on fiber at any rate. Copper could have a
>need for DSO transport I guess and POTS, but I have no interest in that.
>It's too much like hard work to cope with all the variations on POTS unless
>one has that IPR in the bag already., which I don't.
>
>The need for data over circuit will disappear quite quickly once Ethernet
>services are available as a direct alternative (at least that's what we all
>believe in EFM and the MEF, isn't it).
>
>Bob
>
> > -----Original Message-----
> > From: owner-stds-802-3-efm@majordomo.ieee.org
> > [mailto:owner-stds-802-3-efm@majordomo.ieee.org]On Behalf Of Roy Bynum
> > Sent: 10 December 2001 13:08
> > To: ???; stds-802-3-efm@xxxxxxxxxxxxxxxxxx
> > Subject: Re: [EFM] TDM circuit emulation
> >
> >
> >
> > Jangrai,
> >
> > I would be interested in the economics of the efforts that I have been
> > seeing.  With the new chip sets available to build narrowband/wideband
> > cross connects, the cost per T0/E0 per port is going to be very
> > low for the
> > direct simple implementations.  With the issue of jitter compensation,
> > clock tolerance, service overhead, etc, I am nor sure that TDM emulation
> > will pay for itself outside of it being part of other services.  The real
> > problem is that most requirements for TDM emulation are for
> > "Private Line"
> > type of services, which running over packets/frames intermingled
> > with other
> > services and/or other customer's, traffic is hard to qualify as "Private
> > Line" other than name only.  It will be interesting to see how
> > this works out.
> >
> > Thank you,
> > Roy Bynum
> > Orbital View LLC
> >
> > At 12:39 AM 12/10/2001 +0900, ??? wrote:
> >
> > >Hello,
> > >
> > >What do you think of T1/E1 and T3/E3 circuit emulation over EFM?
> > >Some vendors have announced TDM integration over IP.
> > >It might be some problematic in cost/performance due to cost of
> > >delay/jitter compensation. And how about supporting resiliency?
> > >
> > >Jangrai Roh
> >