Subject: about ip header compression on pos

From: 久保田 真 <[email-masked]>
Date: Mon, 21 Feb 2000 19:07:59 +0900

Hello.

I have a doubt about IP header Compression on POS.

Now, there seems to be some Protocol IDs used for IPv4,
- 0x0021:IPv4
- 0x002d:Van Jacobson Compressed TCP/IP
- 0x002f:Van Jacobson Uncompressed TCP/IP
…
and my doubt is about the type used for POS normally?

I think that is '0x0021'.
The reason is that the target of POS is high-speed network,
so  it will have less priority to use compression techniques
and it will have more priority to simplify the system.
right?

I will appliciate anyone's help.

Thanks in advance.

---

From: James Carlson <[email-masked]>
Date: 21 Feb 2000 11:28:15 -0500

> and my doubt is about the type used for POS normally?

I know of no implementations of VJ header compression for SONET/SDH
links.  This would seem to me to be a pointless excercise.

> and it will have more priority to simplify the system.

No.  The problem is that VJ compression works well only when there are
a very small number of TCP flows over the link and the packets are
relatively small (as with interactive TELNET/rlogin traffic).  Given
that most POS links have hundreds or thousands of flows and little
interactive data, VJ compression does no good.

-- 
James Carlson, System Architect                     <[email-masked]>
IronBridge Networks / 55 Hayden Avenue   71.246W   Vox:  +1 781 372 8132
Lexington MA  02421-7996 / USA           42.423N   Fax:  +1 781 372 8090
"PPP Design and Debugging" --- http://people.ne.mediaone.net/carlson/ppp