Subject: RFC 1619 - POS

From: "Mierloi, Cirus G, NPG NCIO" <[email-masked]>
Date: Sun, 31 May 1998 23:51:04 -0400

Hi,

I research possible implementation of POS in a large TCP/IP environment. I
would like to know what is the standardization state and status of this
protocol.

Can you point out any information resources and/or examples of successful
implementation of 
TCP/IP over SONET?

What is the highest line rate at which existing equipment works for POS (is
it OC-192?). 
Any integration issues? 

Any help is appreciated! 

Cirus Mierloi 
AT&T
(908)234-4804

---

From: Tony Li <[email-masked]>
Date: 01 Jun 1998 01:38:45 -0700

> would like to know what is the standardization state and status of this

The PPP portion is of course already a standard.  The SONET encapsulation
has been implemented by at least Cisco in boards for the 7500 (OC-3) and
12000 (OC-3 and OC-12).  I believe that Ascend has also implemented OC-3,
but am unaware of any interoperability testing.

There was an issue about the payload scrambler that has been resolved and I
believe that there is widespread (but not unanimous ;-) consensus on the
x^43+1 scrambler.

> implementation of TCP/IP over SONET?

I believe that Sprintlink has widely deployed this technology in its backbone.

> What is the highest line rate at which existing equipment works for POS (is

I'm unaware of anyone shipping anything faster than OC-12 today, tho have
seen several claims.  There are some interesting issues with running the
HDLC portion of the spec at OC-192 having to do with byte stuffing at that
rate.  The result may be a slightly different encoding at that rate.

> Any integration issues? 

The primary issue that I know of is the payload scrambler.  Early cards do
not support the payload scrambler.  Newer cards may be forced to have a
disableable scrambler.

Tony

p.s. While I do monitor this technology, I certainly don't claim to be an
authoritative source for all relevant data, either public or private.
Updates are most welcome.