Subject: [p2p-sip] SIP, ICE, and an Overlay Network

From: slavitch at objectworld.com (Michael Slavitch)
Date: Wed, 15 Mar 2006 18:11:02 -0500

"Try talking to a college-boy who's behind a double-NAT, which is
happening a lot now at universities (one at the University level, one
for the dorm room), and I'll bet you find Skype works a lot better." 

I am at VON right now, in a conference room at the San Jose Convention
Centre, and it's got NATs and things up the yingyang. I'm at the
conference, but in the exhibit hall my employer has a live system
running our software. 
We had to work at it to get around things not under our control. It
required configuration.  Not much, but some. 
And we consider this a selling point, because our competitors have far
more complicated deployment scenarios.  
Other organizations have canned demos at the show.

Now, with Skype, I just turned it on and it worked. That speaks volumes.
This is now an industry requirement, period.

M

Michael Slavitch           Lead, Strategic Initiatives 
slavitch at objectworld.com   Objectworld Communications Corp. 
+1.613.599.9698 .225       Ottawa, Ontario, Canada

-----Original Message-----
From: p2p-sip-bounces at cs.columbia.edu
[mailto:p2p-sip-bounces at cs.columbia.edu] On Behalf Of Dean Willis
Sent: March 15, 2006 2:58 PM
To: Juha Heinanen
Cc: 'P2P-SIP'
Subject: Re: [p2p-sip] SIP, ICE, and an Overlay Network

On Mar 15, 2006, at 4:18 PM, Juha Heinanen wrote:

> Dean Willis writes:
>
>> Yes. You'd also add a TURN component (see latest draft) into your 
>> proxy, and voila, symmetric NAT traversal.
>
> dean,
>
> today there are large number (perhaps hundreds) of open source 
> ser/openser SIP proxies deployed today that achieve NAT traversal 
> without any need for STUN in the UAs or in the network.
>
> they automatically detect from via and contact headers and source IP 
> addresses/ports if an UA is behind any kind of NAT and if so, start 
> sending requests and replies to its public IP address.
>
> since this is currently working well (equal to Skype), what added 
> values (complexity does not count) does STUN offer here?

Try talking to a college-boy who's behind a double-NAT, which is
happening a lot now at universities (one at the University level, one
for the dorm room), and I'll bet you find Skype works a lot better.

Off-topic for P2P, perhaps, but we've found any number of deployments
(I've been supporting UA design for Vonage, AT&T, and other deployments
that use some Linksys gear) where this doesn't work all that well. The
main issue is keepalive, and STUN (in combination with the "outbound"
draft) gives us a much better answer for keepalive than sending a
REGISTER request every 20 seconds does.

That said, what you're using in SER is essentially a mini-STUN. STUN
uses the same fundamental NAT detection technique, gives feedback also
to the UA about its NATness, and generally just solves a few more cases,
while maintaining good efficiency levels.

This stuff is finally starting to come together into a generally-
workable solution. No perfect, but much better than the amalgamated glop
that has hampered broad-scale deployments for the the pas few years.

--
Dean
_______________________________________________
p2p-sip mailing list
p2p-sip at cs.columbia.edu
https://lists.cs.columbia.edu/cucslists/listinfo/p2p-sip

-- 

-----------------------------------------------

This transmission (including any attachments) may contain confidential information, privileged material (including material protected by the solicitor-client or other applicable privileges), or constitute non-public information. Any use of this information by anyone other than the intended recipient is prohibited. If you have received this transmission in error, please immediately reply to the sender and delete this information from your system. Use, dissemination, distribution, or reproduction of this transmission by unintended recipients is not authorized and may be unlawful. 

Any views, opinions and content presented in this e-mail are solely those of the author and may not represent those of Objectworld Communications Corp.

---

From: jh at tutpro.com (Juha Heinanen)
Date: Thu, 16 Mar 2006 01:20:22 +0200

> This is now an industry requirement, period.

you have to be more specific:  what makes Skype work in your environment
better than openser NAT traversal solution?

-- juha

---

From: dean.willis at softarmor.com (Dean Willis)
Date: Wed, 15 Mar 2006 18:00:15 -0600

> better than openser NAT traversal solution?

Nailed-up TCP connections and coaxial media-and-signaling, usually.

--
Dean

---

From: slavitch at gmail.com (Michael Slavitch)
Date: Wed, 15 Mar 2006 16:18:13 -0800

"you have to be more specific:  what makes Skype work in your environment
better than openser NAT traversal solution?"

The people I need to talk to use Skype.  Nobody that I need to talk to
even knows openser exists, apart from a few alpha geeks, and even
those alpha geeks use Skype because it's easier, the Skype client is
better, and Skype is what their girlfriends use.

Every non-American that I meet at these VON sessions has a Skype ID.
It is ubiquitous, in wide use, and it just works, and consumers love
it.  Mine is running live streaming video right now.

A few moments ago I got to see another conference in a different room.
 Another Skype user turned on Skype Video, turned around his camera,
and I got to see full motion video of the session in a room on the
other side of the conference center:   High- resolution high frame
rate video with excellent sound (muted).  Skype figured out that both
nodes are on the same LAN:  My IP is 10.75.103.247, the other
something else, and there was no delay or jitter.  I turned my camera
around and we got to see two conferences at the same time.
 It was brilliant.

Meanwhile, the session I was in, on venture capital,  had an animated
discussion about how commoditization isn't a good investment vehicle. 
The irony was quite interesting.

In between these two sessions is a  is an exhibit hall where companies
are selling expensive hardware and software  that with difficulty will
provision IMS and carrier VOIP such that with a lot of work they may
be able to offer this service, for a fee of course.

But Skype does it now for free.

Whatever P2PSIP is, it had better be better than that.

M

--
Michael Slavitch
Ottawa, Ontario Canada

---

From: jh at tutpro.com (Juha Heinanen)
Date: Thu, 16 Mar 2006 13:19:15 +0200

> better, and Skype is what their girlfriends use.

i tried to ask, why Skype's NAT traversal is technically better than
openser's.  what i have heard about Skype is that it uses very similar
technology, except that mediaproxies are distributed to customers'
computers.

 > it.  Mine is running live streaming video right now.

the only problem with Skype is that it is proprietary and perhaps also
patented technology.  i, and may be also IETF, believe in open systems.
for this same reason i don't use Windows either.  but if you have
already sold your soul to MicroSoft, you may as well sell it to Skype
too.

-- juha

---

From: aki.niemi at nokia.com (Aki Niemi)
Date: Thu, 16 Mar 2006 14:15:42 +0200

Hi Juha,

> technology, except that mediaproxies are distributed to customers'

I think the main additional thing is that Skype also does a bunch of,
say, "politically incorrect" things, like tunnel via HTTP proxies, to
port 443, etc.

Cheers,
Aki

---

From: jh at tutpro.com (Juha Heinanen)
Date: Thu, 16 Mar 2006 14:42:28 +0200

> say, "politically incorrect" things, like tunnel via HTTP proxies, to

how about mapping SIP requests and replies into XML-RPC?

-- juha

---

From: aki.niemi at nokia.com (Aki Niemi)
Date: Thu, 16 Mar 2006 14:50:42 +0200

> how about mapping SIP requests and replies into XML-RPC?

Heh, yes. Or vice versa, finally defining that DO method to SIP for
carrying XMLRPC. :)

Cheers,
Aki

---

From: jh at tutpro.com (Juha Heinanen)
Date: Thu, 16 Mar 2006 15:20:24 +0200

> Heh, yes. Or vice versa, finally defining that DO method to SIP for

i don't know about do.  what i meant is that you map INVITE to XML-RPC
function called sip.INVITE, etc.  then SIP Proxy would become an XML-RPC
server, which listens at port 80 and/or 443.

-- juha