Subject: [Simple] firewall traversal

From: Jonathan Rosenberg <[email-masked]>
Date: Tue, 13 Feb 2001 00:14:53 -0500

Folks,

Right now, the presence and IM documents are fairly silent on firewall/NAT
traversal. I don't think its that hard, in fact. I wrote a draft recently on
traversal for SIP for media, which is worth a look:

http://search.ietf.org/internet-drafts/draft-rosenberg-sip-entfw-00.txt

Much of this is NOT needed for IM and presence, particularly, all the stuff
relating to RTP.

What is needed from this draft is:

1. usage of persistent TCP or TLS connections between clients and servers,
initiated by the clients
2. The magic cookie contact header hack (a very generally useful feature)

No special forwarders or content rewriting. 

Should we include some text on this in the presence and IM documents
themselves?

-Jonathan R.

---
Jonathan D. Rosenberg                       72 Eagle Rock Ave.
Chief Scientist                             First Floor
dynamicsoft                                 East Hanover, NJ 07936
[email-masked]                     FAX:   (973) 952-5050
http://www.cs.columbia.edu/~jdrosen         PHONE: (973) 952-5000
http://www.dynamicsoft.com

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From: "Henning G. Schulzrinne" <[email-masked]>
Date: Tue, 13 Feb 2001 09:43:43 -0500

> Should we include some text on this in the presence and IM documents

Might be helpful. Also, I found that ssh port forwarding works pretty
well for TCP, without (for SIP) requiring anything but a default
outbound proxy configuration.

-- 
Henning Schulzrinne   http://www.cs.columbia.edu/~hgs