Hi, I came accros one Nokia-S60 Guideline regarding SIP setting in the NAT/Firewall traversal section which say:"It is recommended to use TCP as the transport instead of UDP since even doubled battery life can be achieved with a UI always connected to a SIP service". I need OPenSER users to comment on this since what i know is that UDP is more reliable transportation. WBR lu.
I encountered few problems using Nokia's UDP implementation when there are NATs around so I would recommend you to use TCP. Maybe recent versions have solved this issue but you can find older implementations on the field... Regarding reliability and batery life I would say TCP is more reliable by itself and you will avoid UDP's retransmissions which can safe some batery if the server does not respond fast or there's a problem in the link.
hope it helps, sam
2007/11/12, lu luzango.mfupe@tuune.mobi:
Hi, I came accros one Nokia-S60 Guideline regarding SIP setting in the NAT/Firewall traversal section which say:"It is recommended to use TCP as the transport instead of UDP since even doubled battery life can be achieved with a UI always connected to a SIP service". I need OPenSER users to comment on this since what i know is that UDP is more reliable transportation. WBR lu.
Users mailing list Users@lists.openser.org http://lists.openser.org/cgi-bin/mailman/listinfo/users
I came accros one Nokia-S60 Guideline regarding SIP setting in the NAT/Firewall traversal section which say:"It is recommended to use TCP as the transport instead of UDP since even doubled battery life can be achieved with a UI always connected to a SIP service".
I cannt comment on the battery life issue, but the problem is with IP fragmentation. In case a message is fragmented because it exceeds the MTU size there is a good chance that the fragmented packets cannot traverse the firewall. This is because the port information is not repeated in fragmented packets.
regards Franz
Well -- this kind of surprises me. I would explain that of myself as the handset guys were worried about UDP timers in firewalls being set more aggressively, and addressed that by more frequent keep-alives for UDP which consume more power, that's still guessing though.
-jiri
At 13:20 12/11/2007, franz.edler@inode.at wrote:
I came accros one Nokia-S60 Guideline regarding SIP setting in the NAT/Firewall traversal section which say:"It is recommended to use TCP as the transport instead of UDP since even doubled battery life can be achieved with a UI always connected to a SIP service".
I cannt comment on the battery life issue, but the problem is with IP fragmentation. In case a message is fragmented because it exceeds the MTU size there is a good chance that the fragmented packets cannot traverse the firewall. This is because the port information is not repeated in fragmented packets.
regards Franz
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-- Jiri Kuthan http://iptel.org/~jiri/
franz.edler@inode.at writes:
I cannt comment on the battery life issue, but the problem is with IP fragmentation.
tcp's better battery life may be related to the fact that if the phone is behind nat, the phone itself will keepthe nat binding open by sending every 20 MINUTES or so a keepalive message to the proxy. if you use udp, proxy must nat ping the phone from the proxy once at about 20 SECONDS.
-- juha
Juha Heinanen schrieb:
franz.edler@inode.at writes:
I cannt comment on the battery life issue, but the problem is with IP fragmentation.
tcp's better battery life may be related to the fact that if the phone is behind nat, the phone itself will keepthe nat binding open by sending every 20 MINUTES or so a keepalive message to the proxy.
Does NAT devices keep TCP bindings open for 20 minutes if there is no traffic?
regards klaus
if you use udp, proxy must nat ping the phone from the proxy once at about 20 SECONDS.
-- juha
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Hi,
* Juha Heinanen jh@tutpro.com [071113 08:51]:
Klaus Darilion writes:
Does NAT devices keep TCP bindings open for 20 minutes if there is no traffic?
yes, most nats have much longer tcp timeouts than udp timeouts.
... and there are also some routers and sysadmins without mentioning names that keep TCP timers to less then 30 seconds before they kill the tcp connection if it's idle.
- Atle
(who has bad experience with tcp keepalive above 30 seconds...)
-
Atle Samuelsen -
franz.edler＠inode.at -
jh＠tutpro.com -
Jiri Kuthan -
Klaus Darilion -
lu -
samuel