>Date: Sat, 11 Oct 2003 22:07:49 -0700 >To: asterisk-users@lists.digium.com >From: John Todd <jtodd@loligo.com> >Subject: RE: [Asterisk-Users] SIP / IAX over satellite > >[post re-ordered chronologically] > >>-----Original Message----- >>From: asterisk-users-admin@lists.digium.com >>[mailto:asterisk-users-admin@lists.digium.com] On Behalf Of Tilghman >>Lesher >>Sent: Saturday, October 11, 2003 4:03 PM >>To: asterisk-users@lists.digium.com >>Subject: Re: [Asterisk-Users] SIP / IAX over satellite >> >> >>On Saturday, Oct 11, 2003, at 17:04 America/Chicago, Paul Mahler wrote: >> >>> Which satellite system? >>> >>> I think you need some specialized support, even special hardware. >>> Check >>> out >>> >>> http://www.groundcontrol.com/igvoip_001.htm >>> >>> You may need to replace TCP/IP >>> >> > http://www.mentat.com/skyx/skyx-gateway.html >> >>I don't know why he'd need to replace TCP/IP when both SIP as well as >>IAX use UDP/IP. There may be substantial latency, however. >> >>-Tilghman > > >>Well, it's that stack that needs to go. Check out the link. >> >>Paul >> >> >>Paul Mahler >>pmahler@signate.com >>phone: 650-207-9855 >>fax: 877-408-0105 > > >It's unlikely that the TCP/IP stack "needs to go". IP applications >work quite well over satellite, no matter what people tell you. >They just get really, really slow if they're TCP due to ACK response >delay, and UDP has the aforementioned 500ms lag as well. > >The skyx stuff is just a forward-ACKing spoofer for TCP, and >probably some smart squid derivatives to boost HTTP transfer speeds. >Not useful for VoIP, but probably useful if you're doing anything >that's not UDP based. > >For VoIP with IAX, there may be application layer issues that are >smudging your results. I would suggest that you try to get SIP >working over satellite, as I have had that working with no >difficulty in the past (excepting the delay issues, of course.) If >you can get "raw" RTP working with SIP, but not IAX2, then perhaps >the issue needs to be patched in the IAX source code if there is >some timer that is expiring inside the IAX protocol. Let us know >how your results with SIP work. > >Again: VoIP works JUST FINE over satellite, at least as far as the >voice quality goes, as long as you have decent bandwidth available. >Latency is another issue, but there's nothing you're going to be >able to do when you're pushing a radio wave 33,000 miles out and >33,000 miles back - physics doesn't allow for better QoS. :-) > >JTOf course, I meant 22,237 and not 33,000 miles. Bad typing day. JT
Hi all, -------- thank U all for your very fast response. I want to clarify that my question was not regarding about the fasibility of Voip over satellite in general but especial the behavior of the Asterisk PBX on a long delay path. We just successfully tested H323 Voip with a Innovaphone IP 2000 over satellite to a Innovaphone PSTN Gayteway. It works fine if you be aware about the > 500 ms RTT and you are ready to train youself a little bit in conversation discipline. BTW. We are operating a DVB hub station over SESAT 36 E on transponder G6, Ku band. SESAT "hangs " directly over Sibirea and covers with his wide beam all of Europe and most of Asia and the north part of Africa. We have 8 MHz space segment and using 64 - 384 kBits FDMA DAMA in the return channel. The reason for the registration timeouts can probably in a very short programmed "registration timer". Maybe somebody of you is familiar with the Asterisk source code and knows which of the "wheels" I have to turn. It would help me very much. (:-) I would prefer to use SIP rather than IAX over satellite because I am more familar with it. To diagnose this behaviour I will test the satellite link with the SIP test tool SipSak (http://sipsak.berlios.de) and later with a network link simulator to increase the propagation delay step by step until the SIP registration times out. First of all I will test a Snom-2-Snom direct connection without any SIP registrator or proxy. I this works the debugging can go on. BTW. If somebody of you knows how to configure the setup below in iax.conf and extensions.conf I would be very happy, because it would spare a lot of time for me with trials and errors. (Sip configuration is clear) Snom-Office ------SIP----- *-Office ------ IAX --- SAT ----IAX ----*-Field--- SIP--- Snom-Filed many regards Olaf <http://dict.leo.org/?p=lURE.&search=feasibility>
Uriel Carrasquilla
2003-Oct-12 21:06 UTC
Fwd: RE: [Asterisk-Users] SIP / IAX over satellite
Ku is very sensitive to rain fade or big cities with a lot of polution. I have always used C band. 8 MHz (by 2 to make it duplex)would be taken very fast by SIP unless a well balance CODEC is used (such as g729). Also make sure that there is no double compression going on. Regards, Uriel -----Original Message----- From: asterisk-users-admin@lists.digium.com [mailto:asterisk-users-admin@lists.digium.com]On Behalf Of Olaf Menzel Sent: Sunday, October 12, 2003 6:02 AM To: asterisk-users@lists.digium.com; esa.momosat@horz.de; esa.momosat@horz.de; karl.jonas@ieee.org Subject: Re: Fwd: RE: [Asterisk-Users] SIP / IAX over satellite Hi all, -------- thank U all for your very fast response. I want to clarify that my question was not regarding about the fasibility of Voip over satellite in general but especial the behavior of the Asterisk PBX on a long delay path. We just successfully tested H323 Voip with a Innovaphone IP 2000 over satellite to a Innovaphone PSTN Gayteway. It works fine if you be aware about the > 500 ms RTT and you are ready to train youself a little bit in conversation discipline. BTW. We are operating a DVB hub station over SESAT 36 E on transponder G6, Ku band. SESAT "hangs " directly over Sibirea and covers with his wide beam all of Europe and most of Asia and the north part of Africa. We have 8 MHz space segment and using 64 - 384 kBits FDMA DAMA in the return channel. The reason for the registration timeouts can probably in a very short programmed "registration timer". Maybe somebody of you is familiar with the Asterisk source code and knows which of the "wheels" I have to turn. It would help me very much. (:-) I would prefer to use SIP rather than IAX over satellite because I am more familar with it. To diagnose this behaviour I will test the satellite link with the SIP test tool SipSak (http://sipsak.berlios.de) and later with a network link simulator to increase the propagation delay step by step until the SIP registration times out. First of all I will test a Snom-2-Snom direct connection without any SIP registrator or proxy. I this works the debugging can go on. BTW. If somebody of you knows how to configure the setup below in iax.conf and extensions.conf I would be very happy, because it would spare a lot of time for me with trials and errors. (Sip configuration is clear) Snom-Office ------SIP----- *-Office ------ IAX --- SAT ----IAX ----*-Field--- SIP--- Snom-Filed many regards Olaf <http://dict.leo.org/?p=lURE.&search=feasibility> _______________________________________________ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users