Folks,
In our tests in our labs of various SIP devices, we have been increasing
discovering that people have introduced arbitrary length restrictions on
various SIP fields. For example, we have discovered that one vendor limits
the length of the branch ID to 16 bytes. If it gets more than that, it
rejects the request. We ran into this when trying to test out the recent
proposal for adding uniqueness to the branch ID. Very bad.
I cannot emphasize enough the scope of this implementation error. It is a
recipe for interoperability nightmares. Over time, people find additional
uses and data types they would like to stick in various fields. Branch ID is
one that is particularly nice, for example. As these field usages get
larger, and press against these artificial barriers, you severely limit the
growth of the protocol, and its overall interoperability. These problems are
extremely hard to find and always come up years later.
The SIP spec in no way whatsoever says that tokens and other assorted
constructions are limited in length. If your implementation barfs on things
like this, it is NON-COMPLIANT to rfc2543. Please, folks, fix these things.
Thanks,
Jonathan R.
---
Jonathan D. Rosenberg 72 Eagle Rock Ave.
Chief Scientist First Floor
dynamicsoft East Hanover, NJ 07936
[EMAIL PROTECTED] FAX: (973) 952-5050
http://www.cs.columbia.edu/~jdrosen PHONE: (973) 952-5000
http://www.dynamicsoft.com
