[standards-jig] Re: Standards-JIG digest, Vol 1 #443 - 2 msgs

Jean-Louis Seguineau/EXC/TEC jean-louis.seguineau at antepo.com
Sat Jan 25 16:58:57 UTC 2003


You're welcome.

You're on the right track in using XMPP for negotiating the call (allthough
you may face competition from SIP outside the Jabber world)
On the codec side, the industry standards are the one used under H323 (all
these G's at the end) and my guess is you should find a number of open
source implementation for them. Alternatively, you have most of them already
built into windows (I know...)

--jean-louis

----- Original Message ----- > Message:
> From: "Vapor" <vapor at 66oc.org>
> To: <standards-jig at jabber.org>
> Subject: Re: [standards-jig] Re:H.323 vs SIP for Jabber
> Date: Fri, 24 Jan 2003 16:24:02 -0600
> Reply-To: standards-jig at jabber.org
>
> THANKYOU very much Jean-Louis.  That is exactly the kind of information I
> have been scouring for.  I was quite confused as to the significants of
SIP
> and how exactly it carried voice.  So if all SIP is used for is
negotiating
> and setting up the call then we really could get away with using XMPP.
>
> So really we should look at using RTP or something similar, which I
believe
> there is already a JEP for and we should look at negotiating RTP over
XMPP.
> If we do this right, a SIP gateway for negotiating voice with SIP enabled
> voice software should work fine.
>
> I kinda feel like I am back to square one but this time I know which
> direction not to go :-)
>
> Anybody know where we can find industry standardized codecs for voice
> compression?
>
> Vapor
> ----- Original Message -----
> From: "Jean-Louis Seguineau/EXC/TEC" <jean-louis.seguineau at antepo.com>
> To: <standards-jig at jabber.org>
> Sent: Friday, January 24, 2003 3:26 PM
> Subject: [standards-jig] Re:H.323 vs SIP for Jabber
>
>
> > Hi,
> >
> > Allow me to somehow temper the comparizon you have made between H323 and
> > SIP. They were intended to both be signaling protocols, but H323 has got
> > things a little bit mixed up as it also standardize the transport.
> >
> > The H.323 standard allow transfer of multimedia streams over packet
> > networks. It is a descriptive standard and applies only to multimedia
> > communication, which include voice. It runs over a large number of
packet
> > infrastructure which include among others IP, Frame Relay or ATM.
> > It was originally developed as an adaptation of H.320, which
> > addresses videoconferencing over ISDN and other circuit switched
networks
> > and services. Since H.320 was ratified, H.323 has evolved beyond a
logical
> > and necessary extension of the H.320 standard to include Corporate
> Intranets
> > and packet-switched networks generally. H.323 utilizes the Real-Time
> > Protocol (RTP/RTCP) from the IETF, along with internationally
standardized
> > codecs. Since version 2, H.323 is also being used for video and other
> > communications, over the Internet.
> >
> > In common with the other ITU multimedia teleconferencing standard, H.323
> > applies to multipoint and point-to-point sessions. H323 is only a
> > description standard that include a large number of other specialized
> > standards, such as
> >
> > H.225.0      Specifies messages for call control including signaling,
> > registration
> > and admissions, and packetization/ synchronization of media streams
> > H.245  Specifies messages for opening and closing channels for media
> > streams,
> > and other commands, requests and indications.
> > H.450.x     Series of Suplimentary service recommendations. Defines
> > signalling and
> > procedures used to provide these telephony-like services
> > H.235     Defines the security framework used to provide authentication,
> > encryption and integrity to H.323 systems
> > H.332     Provides large scale, or loosely-coupled conferencing based
upon
> > H.323.
> > H.261     Video codec for audiovisual services at P x 64 Kbps.
> > H.263     Specifies a new video codec for video over POTS.
> > G.711     Audio codec, 3.1 KHz at 48, 56, and 64 Kbps (normal
telephony).
> > G.722     Audio Codec, 7 KHz at 48, 56, and 64 Kbps.
> > G.723     Audio Codec, for 5.3 and 6.3 Kbps modes
> > G.728     Audio Codec, 3.1 KHz at 16 Kbps.
> > G.729     Audio Codec, 8 kbps audio codec.
> >
> > So comming back to your statement
> > > H.323
> > >  Pros:
> > >  Very Generalized And Fexible
> > >  Allows for Voice, Video and many other possible facets
> > >  Specifies Multipoint Control Unit protocols for Bridging or =
> > > Conferencing
> > >  Specifies interfacing with many other carrier methods outside of
TCP/IP
> > >  Large Industry Support
> >
> > H323 is as you said blotted, not flexible at all, as everybody can plug
> > anything (messy does not mean flexible :) In addition, its
implementations
> > are often proprietary, and the interconection with different carriers
> > somewhat ectic. The industry support comes from the fact that many
> > manufacturer made the same mistake...
> >
> > On the othe hand, SIP as it names implies was originaly intended to
> > establish communication session between to party. It does not provides
any
> > transport mechanism for an undelying communication media. It just allow
> the
> > party to agree on a communication. But the actual media transport will
> need
> > to be carried out by a dedicated transport such as RTP, or any streaming
> > media protocol.
> > SIP is only handling the call establishement part in a VOIP call, the
call
> > itself runs on a separate stream. In short, SIP never transport any VOIP
> by
> > itself but negotiate the establishement of a RTP session to carry VOIP.
> >
> > This is where SIP is better that H323.
> >
> > I would therefore rephrase a little your statement
> > > SIP
> > >  Pros:
> > >  Very Specific in that it was designed to directly address Voice over
IP
> > >  Maximizes available bandwidth by keeping its messages lean and to the
=
> > > point
> > >  Smaller System Footprint - More focused allowing for less code
required
> =
> > > in its libraries
> > >  Light Weight - can process more call ser second than H.323
> > >  extensible
> > >
> > >  Cons:
> > >  Limited by its very nature to only voice communications
> > > =20
> >
> > SIP is flexible as it can address many signaling needs beyond VOIP. It
is
> > efficient, but it does not transport the voice that need to use another
> > streaming protocol (No VOIP packets are ever transported in SIP packet)
> > It has q wide acceptance in the industry, and there are a large number
of
> > good qulity libraries around. But once again, there is no free VOIP
> > streaming libraries available.
> >
> > But maybe we could come back to the underlying reason for the
comparizon.
> It
> > is impossible to actually use Jabber XMPP to transport VOIP, due to
> several
> > performance issues that will arise(network latency, no guaranted quality
> of
> > service, etc...)
> > But it is possible to use XMPP as a way to negotiate a VOIP session
> between
> > two voice enabled client. It would be for example possible to use the
> > jabber:iq:oob with a specific syntax, then the client would have to
start
> > some streaming protocol between themselves to actually carry the VOIP
> call.
> >
> > Hope it helps clarify the subject
> >
> > --jean-louis
> >
> > ----- Original Message -----
> > > Message: 2
> > > From: "Vapor" <vapor at 66oc.org>
> > > To: <standards-jig at jabber.org>
> > > Date: Thu, 23 Jan 2003 22:19:13 -0600
> > > Subject: [standards-jig] H.323 vs SIP for Jabber
> > > Reply-To: standards-jig at jabber.org
> > >
> > > This is a multi-part message in MIME format.
> > >
> > > ------=_NextPart_000_0059_01C2C32D.75C42A50
> > > Content-Type: text/plain;
> > > charset="iso-8859-1"
> > > Content-Transfer-Encoding: quoted-printable
> > >
> > > I have been doing some research on VoIP and as far as I can see, it
all
> =
> > > seems to come down to H.323 vs SIP.  H.323 I believe has entered
version
> =
> > > 4 if I am correct and I am not exactly familiar with the differences =
> > > between each version but as far as I can see SIP seems to fit with =
> > > Jabber more that H.323.
> > >
> > > Here is a brief Comparison I have made followed by a link to a pdf
that
> =
> > > I found very useful in identifying the differences between the two.
> > >
> > > H.323
> > >  Pros:
> > >  Very Generalized And Fexible
> > >  Allows for Voice, Video and many other possible facets
> > >  Specifies Multipoint Control Unit protocols for Bridging or =
> > > Conferencing
> > >  Specifies interfacing with many other carrier methods outside of
TCP/IP
> > >  Large Industry Support
> > >
> > >  Cons:
> > >  Bloated - Desires to Address Everything, including little obscure =
> > > protocols that may have no Relevance to Jabber
> > >  Noisy - Can cause lots of uncessesary traffic on a network
> > >  Large System Footprint - Because of its extreme generalization, it =
> > > requires rather large libraries to implement it properly.
> > >  Overly Complex
> > >  Requires gatekeepers to manage calls
> > >  Difficult to troubleshoot due to its complexity
> > >
> > >
> > > SIP
> > >  Pros:
> > >  Very Specific in that it was designed to directly address Voice over
IP
> > >  Maximizes available bandwidth by keeping its messages lean and to the
=
> > > point
> > >  Smaller System Footprint - More focused allowing for less code
required
> =
> > > in its libraries
> > >  Light Weight - can process more call ser second than H.323
> > >  extensible
> > >
> > >  Cons:
> > >  Limited by its very nature to only voice communications
> > > =20
> > > http://www.sipcenter.com/files/Wind_River_SIP_H323.pdf
> > >
> > > I am still researching but so far it looks to me that if Jabber were
to
> =
> > > adopt a single standard for clients to use for VoIP integration that
SIP
> =
> > > should probably be it.  And with the development of XMPP over SIP,
this
> =
> > > makes the choice even more logical. =20
> > >
> > > Again, I am not proposing that we should integrate SIP and VoIP into
the
> =
> > > Jabber server, but if the Jabber Software Foundation were to adopt a =
> > > single VoIP protocol as its recommended standard for implementing
voice,
> =
> > > that VoIP actually begin to creep its way into more clients than just
=
> > > Enigma 3.
> > >
> > > I am still looking for some suitable open source implementations of
SIP
> =
> > > servers to recommend to Jabber server administators that want to offer
=
> > > SIP and I do thing there may need to be some way for the Jabber server
=
> > > to inform that client where the SIP server is.  This may just need to
be
> =
> > > a transport or component of some sort.
> > >
> > > Vapor
> > > ------=_NextPart_000_0059_01C2C32D.75C42A50
> > > Content-Type: text/html;
> > > charset="iso-8859-1"
> > > Content-Transfer-Encoding: quoted-printable
> > >
> > > <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
> > > <HTML><HEAD>
> > > <META http-equiv=3DContent-Type content=3D"text/html; =
> > > charset=3Diso-8859-1">
> > > <META content=3D"MSHTML 6.00.2800.1126" name=3DGENERATOR>
> > > <STYLE></STYLE>
> > > </HEAD>
> > > <BODY bgColor=3D#ffffff>
> > > <DIV><FONT face=3DArial size=3D2>I have been doing some research on
VoIP
> =
> > > and as far=20
> > > as I can see, it all seems to come down to H.323 vs SIP.  H.323 I
=
> > > believe=20
> > > has entered version 4 if I am correct and I am not exactly familiar
with
> =
> > > the=20
> > > differences between each version but as far as I can see SIP seems to
=
> > > fit with=20
> > > Jabber more that H.323.</FONT></DIV>
> > > <DIV><FONT face=3DArial size=3D2></FONT> </DIV>
> > > <DIV><FONT face=3DArial size=3D2>Here is a brief Comparison I have
made
> =
> > > followed by=20
> > > a link to a pdf that I found very useful in identifying the
differences
> =
> > > between=20
> > > the two.</FONT></DIV>
> > > <DIV><FONT face=3DArial size=3D2></FONT> </DIV>
> > > <DIV><FONT face=3DArial size=3D2>H.323<BR> Pros:<BR> Very =
> > > Generalized And=20
> > > Fexible<BR> Allows for Voice, Video and many other possible=20
> > > facets<BR> Specifies Multipoint Control Unit protocols for
Bridging
> =
> > > or=20
> > > Conferencing<BR> Specifies interfacing with many other carrier =
> > > methods=20
> > > outside of TCP/IP<BR> Large Industry Support</FONT></DIV>
> > > <DIV> </DIV>
> > > <DIV><FONT face=3DArial size=3D2> Cons:<BR> Bloated -
Desires
> =
> > > to Address=20
> > > Everything, including little obscure protocols that may have no =
> > > Relevance to=20
> > > Jabber<BR> Noisy - Can cause lots of uncessesary traffic on a=20
> > > network<BR> Large System Footprint - Because of its extreme =
> > > generalization,=20
> > > it requires rather large libraries to implement it =
> > > properly.<BR> Overly=20
> > > Complex<BR> Requires gatekeepers to manage
calls<BR> Difficult
> =
> > > to=20
> > > troubleshoot due to its complexity</FONT></DIV>
> > > <DIV> </DIV><FONT face=3DArial size=3D2>
> > > <DIV><BR>SIP</DIV>
> > > <DIV> Pros:<BR> Very Specific in that it was designed to =
> > > directly=20
> > > address Voice over IP<BR> Maximizes available bandwidth by
keeping
> =
> > > its=20
> > > messages lean and to the point<BR> Smaller System Footprint -
More
> =
> > > focused=20
> > > allowing for less code required in its libraries<BR> Light
Weight -
> =
> > > can=20
> > > process more call ser second than H.323<BR> extensible</DIV>
> > > <DIV> </DIV>
> > > <DIV> Cons:<BR> Limited by its very nature to only voice=20
> > > communications<BR> </FONT></DIV>
> > > <DIV><FONT face=3DArial size=3D2><A=20
> > >
> href=3D"http://www.sipcenter.com/files/Wind_River_SIP_H323.pdf">http://ww=
> > > w.sipcenter.com/files/Wind_River_SIP_H323.pdf</A></FONT></DIV>
> > > <DIV><FONT face=3DArial size=3D2></FONT> </DIV>
> > > <DIV><FONT face=3DArial size=3D2>I am still researching but so far it
=
> > > looks to me=20
> > > that if Jabber were to adopt a single standard for clients to use for
=
> > > VoIP=20
> > > integration that SIP should probably be it.  And with the =
> > > development of=20
> > > XMPP over SIP, this makes the choice even more logical.  =
> > > </FONT></DIV>
> > > <DIV><FONT face=3DArial size=3D2></FONT> </DIV>
> > > <DIV><FONT face=3DArial size=3D2>Again, I am not proposing that we =
> > > should integrate=20
> > > SIP and VoIP into the Jabber server, but if the Jabber Software =
> > > Foundation were=20
> > > to adopt a single VoIP protocol as its recommended standard for =
> > > implementing=20
> > > voice, that VoIP actually begin to creep its way into more clients
than
> =
> > > just=20
> > > Enigma 3.</FONT></DIV>
> > > <DIV><FONT face=3DArial size=3D2></FONT> </DIV>
> > > <DIV><FONT face=3DArial size=3D2>I am still looking for some suitable
=
> > > open source=20
> > > implementations of SIP servers to recommend to Jabber server =
> > > administators that=20
> > > want to offer SIP and I do thing there may need to be some way for the
=
> > > Jabber=20
> > > server to inform that client where the SIP server is.  This may =
> > > just need=20
> > > to be a transport or component of some sort.</FONT></DIV>
> > > <DIV><FONT face=3DArial size=3D2></FONT> </DIV>
> > > <DIV><FONT face=3DArial size=3D2>Vapor</FONT></DIV></BODY></HTML>
> > >
> > > ------=_NextPart_000_0059_01C2C32D.75C42A50--
> > >
> > >
> > >
> > > -- __--__--
> > >
> > > Message: 3
> > > Date: Fri, 24 Jan 2003 08:33:36 +0100
> > > From: Jacek Konieczny <jajcus at bnet.pl>
> > > To: standards-jig at jabber.org
> > > Subject: Re: [standards-jig] H.323 vs SIP for Jabber
> > > Reply-To: standards-jig at jabber.org
> > >
> > > On Thu, Jan 23, 2003 at 10:19:13PM -0600, Vapor wrote:
> > > > SIP
> > > >  Pros:
> > > >  Very Specific in that it was designed to directly address Voice
over
> IP
> > > >  Maximizes available bandwidth by keeping its messages lean and to
the
> > point
> > > >  Smaller System Footprint - More focused allowing for less code
> required
> > in its
> > > > libraries
> > > >  Light Weight - can process more call ser second than H.323
> > > >  extensible
> > > >
> > > >  Cons:
> > > >  Limited by its very nature to only voice communications
> > > This is not true. SIP can be used to initialize any session (but
mostly
> > > multimedia sessions), and even to carry any not-session-related
messages
> > > (eg. SIMPLE which is IM over SIP). I think SIP is much more generic
> > > then H323. But the most important thing is that SIP is much simpler
than
> > > H323.
> > >
> > > Greets,
> > > Jacek
> > >
> > >
> > > -- __--__--
> > >
> > > _______________________________________________
> > > Standards-JIG mailing list
> > > Standards-JIG at jabber.org
> > > http://mailman.jabber.org/listinfo/standards-jig
> > >
> > >
> > > End of Standards-JIG Digest
> > >
> >
> >
> > _______________________________________________
> > Standards-JIG mailing list
> > Standards-JIG at jabber.org
> > http://mailman.jabber.org/listinfo/standards-jig
> >
>
>
>
>
> --__--__--
>
> _______________________________________________
> Standards-JIG mailing list
> Standards-JIG at jabber.org
> http://mailman.jabber.org/listinfo/standards-jig
>
>
> End of Standards-JIG Digest
>




More information about the Standards mailing list