20 Sep
2013
20 Sep
'13
4:16 p.m.
I've been spending some time looking at some of the significant
changes Apple has made to Facetime in iOS 7. I'm far from an Apple
fanboy but some of them are pretty interesting:
- multiplexing everything over a single UDP port
- deflate compression with SIP
- various /slight/ protocol violations ;)
More here:
http://blog.krisk.org/2013/09/apples-new-facetime-sip-perspective.html
As SDP bodies swell more and more can we hope to build significant
support for multiplexing and deflate compression in the SIP-focused
open source ecosystem?
--
Kristian Kielhofner
20 Sep
20 Sep
4:28 p.m.
20 sep 2013 kl. 15:16 skrev Kristian Kielhofner <kris(a)kriskinc.com>om>:
I've been spending some time looking at some of
the significant
changes Apple has made to Facetime in iOS 7. I'm far from an Apple
fanboy but some of them are pretty interesting:
- multiplexing everything over a single UDP port
That's what's Google has
done with Hangouts and what we're currently
working on in the IETF to standardize, driven by WebRTC. Will be very
beneficial for all VoIP.
- deflate compression with SIP
- various /slight/ protocol violations ;)
getting depressed....
/O
More here:
http://blog.krisk.org/2013/09/apples-new-facetime-sip-perspective.html
As SDP bodies swell more and more can we hope to build significant
support for multiplexing and deflate compression in the SIP-focused
open source ecosystem?
--
Kristian Kielhofner
_______________________________________________
SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
sr-users(a)lists.sip-router.org
http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
---
* Olle E Johansson - oej(a)edvina.net
* Cell phone +46 70 593 68 51, Office +46 8 96 40 20, Sweden
4:36 p.m.
20 sep 2013 kl. 15:16 skrev Kristian Kielhofner <kris(a)kriskinc.com>om>:
I've been spending some time looking at some of
the significant
changes Apple has made to Facetime in iOS 7. I'm far from an Apple
fanboy but some of them are pretty interesting:
- multiplexing everything over a single UDP port
After reading your very good blog entry (thanks!) I suspect that
they have gone the extra way and mixed SIP/RTP/RTCP due to
carrier grade nats. There's a new RFC describing issues with those
and one is a shortage of ports. Every customer gets only a few
allocations and only one per common port. ONly one SIP phone
on 5060 as an example.
Limiting the number of ports used will not only make firewall
traversal easier, it will make CGN traversal easier. While waiting
for the real stuff - IPv6.
Blog:
http://blog.krisk.org/2013/09/apples-new-facetime-sip-perspective.html
CGN RFC:
http://www.rfc-editor.org/rfc/rfc7021.txt
/O
5:01 p.m.
On Fri, Sep 20, 2013 at 9:36 AM, Olle E. Johansson <oej(a)edvina.net> wrote:
20 sep 2013 kl. 15:16 skrev Kristian Kielhofner <kris(a)kriskinc.com>om>:
I've been spending some time looking at some of the significant
changes Apple has made to Facetime in iOS 7. I'm far from an Apple
fanboy but some of them are pretty interesting:
- multiplexing everything over a single UDP port
After reading your very good blog entry (thanks!) I suspect that
they have gone the extra way and mixed SIP/RTP/RTCP due to
carrier grade nats. There's a new RFC describing issues with those
and one is a shortage of ports. Every customer gets only a few
allocations and only one per common port. ONly one SIP phone
on 5060 as an example.
Limiting the number of ports used will not only make firewall
traversal easier, it will make CGN traversal easier. While waiting
for the real stuff - IPv6.
Blog:
http://blog.krisk.org/2013/09/apples-new-facetime-sip-perspective.html
CGN RFC:
http://www.rfc-editor.org/rfc/rfc7021.txt
/O
Olle,
Great point! I've updated my blog post with this information.
Thanks!
--
Kristian Kielhofner
5:19 p.m.
Hello,
interesting, thanks for sharing!
What else I could say, I am really deeply extremely ... (can't find
other words) ... shocked they don't use SIGCOMP specs [ha ha!]! I
remember some discussions when I said that usage of one well established
compression algoritm will get it done in few hours (implementatio wise)
than what IETF came up with in this regard. Sad but true, many IETF
specs have no touch with reality...
Maybe I missed while quick reading, what are the "various /slight/
protocol violations" you spotted?
Cheers,
Daniel
On 9/20/13 3:16 PM, Kristian Kielhofner wrote:
I've been spending some time looking at some of
the significant
changes Apple has made to Facetime in iOS 7. I'm far from an Apple
fanboy but some of them are pretty interesting:
- multiplexing everything over a single UDP port
- deflate compression with SIP
- various /slight/ protocol violations ;)
More here:
http://blog.krisk.org/2013/09/apples-new-facetime-sip-perspective.html
As SDP bodies swell more and more can we hope to build significant
support for multiplexing and deflate compression in the SIP-focused
open source ecosystem?
--
Daniel-Constantin Mierla - http://www.asipto.com
http://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda
Kamailio Advanced Trainings - Berlin, Oct 21-24; Miami, Nov 11-13, 2013
- more details about Kamailio trainings at http://www.asipto.com -
6:15 p.m.
Hi Daniel,
I know, shocking (heh)!
The protocol violations were very slight - omitting SDP rtpmap lines
for dynamic RTP payloads, omitting a=rtcp-mux for RTP+RTCP mux (but
they're already muxing SIP too, so ehh). Possibly others.
On Fri, Sep 20, 2013 at 10:19 AM, Daniel-Constantin Mierla
<miconda(a)gmail.com> wrote:
Hello,
interesting, thanks for sharing!
What else I could say, I am really deeply extremely ... (can't find other
words) ... shocked they don't use SIGCOMP specs [ha ha!]! I remember some
discussions when I said that usage of one well established compression
algoritm will get it done in few hours (implementatio wise) than what IETF
came up with in this regard. Sad but true, many IETF specs have no touch
with reality...
Maybe I missed while quick reading, what are the "various /slight/ protocol
violations" you spotted?
Cheers,
Daniel
On 9/20/13 3:16 PM, Kristian Kielhofner wrote:
--
Kristian Kielhofner
I've been spending some time looking at some of the significant
changes Apple has made to Facetime in iOS 7. I'm far from an Apple
fanboy but some of them are pretty interesting:
- multiplexing everything over a single UDP port
- deflate compression with SIP
- various /slight/ protocol violations ;)
More here:
http://blog.krisk.org/2013/09/apples-new-facetime-sip-perspective.html
As SDP bodies swell more and more can we hope to build significant
support for multiplexing and deflate compression in the SIP-focused
open source ecosystem?
--
Daniel-Constantin Mierla - http://www.asipto.com
http://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda
Kamailio Advanced Trainings - Berlin, Oct 21-24; Miami, Nov 11-13, 2013
- more details about Kamailio trainings at http://www.asipto.com -
_______________________________________________
SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
sr-users(a)lists.sip-router.org
http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
6:36 p.m.
Hi Kristian,
On 9/20/13 5:15 PM, Kristian Kielhofner wrote:
Hi Daniel,
I know, shocking (heh)!
The protocol violations were very slight - omitting SDP rtpmap lines
for dynamic RTP payloads, omitting a=rtcp-mux for RTP+RTCP mux (but
they're already muxing SIP too, so ehh). Possibly others.
ahh, ok, I remarked your notes about, but somehow I had in mind only the
SIP part (headers), not the SDP body. I was looking to see if they use
some custom format or not-specified values for headers...
Thanks,
Daniel
On Fri, Sep 20, 2013 at 10:19 AM, Daniel-Constantin Mierla
<miconda(a)gmail.com> wrote:
--
Daniel-Constantin Mierla - http://www.asipto.com
http://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda
Kamailio Advanced Trainings - Berlin, Oct 21-24; Miami, Nov 11-13, 2013
- more details about Kamailio trainings at http://www.asipto.com -
Hello,
interesting, thanks for sharing!
What else I could say, I am really deeply extremely ... (can't find other
words) ... shocked they don't use SIGCOMP specs [ha ha!]! I remember some
discussions when I said that usage of one well established compression
algoritm will get it done in few hours (implementatio wise) than what IETF
came up with in this regard. Sad but true, many IETF specs have no touch
with reality...
Maybe I missed while quick reading, what are the "various /slight/ protocol
violations" you spotted?
Cheers,
Daniel
On 9/20/13 3:16 PM, Kristian Kielhofner wrote:
I've been spending some time looking at some
of the significant
changes Apple has made to Facetime in iOS 7. I'm far from an Apple
fanboy but some of them are pretty interesting:
- multiplexing everything over a single UDP port
- deflate compression with SIP
- various /slight/ protocol violations ;)
More here:
http://blog.krisk.org/2013/09/apples-new-facetime-sip-perspective.html
As SDP bodies swell more and more can we hope to build significant
support for multiplexing and deflate compression in the SIP-focused
open source ecosystem?
--
Daniel-Constantin Mierla - http://www.asipto.com
http://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda
Kamailio Advanced Trainings - Berlin, Oct 21-24; Miami, Nov 11-13, 2013
- more details about Kamailio trainings at http://www.asipto.com -
_______________________________________________
SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
sr-users(a)lists.sip-router.org
http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
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6 comments
3 participants
participants (3)
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Daniel-Constantin Mierla -
Kristian Kielhofner -
Olle E. Johansson