Subject: Native encapsulation in MP

From: Ali Irfan-FIA225 <[email-masked]>
Date: Wed, 19 Jul 2000 10:26:48 -0500

Situation: MP is used to bundle multiple links.

My questions are: If a user packet is not fragmented, then can it be sent
native on a link or is the MP encapsulation a must? From my understanding of
RFC1990, native encapsulation is permitted. Am also wondering what is the
most prevalent implementation: native or always MP encapsulated? If  I  do
have a MP implementation which sends non-fragmented PPP frames in native
form, will I have interoperability issues?

Thanks for all the help.

Regards

Irfan

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From: James Carlson <[email-masked]>
Date: Wed, 19 Jul 2000 11:44:05 -0400 (EDT)

Ali Irfan-FIA225 writes:
> native on a link or is the MP encapsulation a must?

It can be sent native.  This is at the top of page 6, RFC 1990.

> From my understanding of
> most prevalent implementation: native or always MP encapsulated?

Most implementations I've used always encapsulate so that datagram
order is preserved.

> If  I  do

You *shouldn't* have interoperability problems with anything but
broken peers.  I haven't seen implementations that have trouble with
network layer data sent unencapsulated.  (I have seen peers that have
odd behavior with respect to whether the PPP negotiation packets -- in
particular, LCP and the NCPs -- are encapsulated.  Unfortunately, this
kind of strangeness seems to vary by vendor and by version number.)

You may have performance problems.  Reordering data on a link can
lower TCP performance.

-- 
James Carlson, Internet Engineering       <[email-masked]>
SUN Microsystems / 1 Network Drive         71.234W   Vox +1 781 442 2084
MS UBUR02-212 / Burlington MA 01803-2757   42.497N   Fax +1 781 442 1677
"PPP Design and Debugging" --- http://people.ne.mediaone.net/carlson/ppp