*Dear All, I run the below tcp dump on my asterisk server tcpdump -i eth0 -n -s0 -v udp port 5060 I got the following result 20:29:48.596867 IP (tos 0x10, ttl 64, id 0, offset 0, flags [DF], proto 17, length: 373) SIP_PROXY_IP.5060 > Asterisk_IP.5060: UDP, length 345 What i need to know please what TTL means specifically and what is the best value og TTL and what is the lengh vale mean Regards* -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.digium.com/pipermail/asterisk-users/attachments/20081215/8540755c/attachment.htm
TTL is part of the UDP header (Time To Live). It isn't really about the voice at all. Length 345 is the number of bytes in the packet. j On Mon, 15 Dec 2008, michel freiha wrote:> *Dear All, > I run the below tcp dump on my asterisk server > > tcpdump -i eth0 -n -s0 -v udp port 5060 > > I got the following result > > 20:29:48.596867 IP (tos 0x10, ttl 64, id 0, offset 0, flags [DF], proto 17, > length: 373) SIP_PROXY_IP.5060 > Asterisk_IP.5060: UDP, length 345 > > What i need to know please what TTL means specifically and what is the best > value og TTL and what is the lengh vale mean > > Regards* >
Hi,
The TTL is the time to live of the IP paquet. But I think that what interests
you is the SIP_TIMEOUT which is by default 3600 seconds. but you can modify it.
________________________________
De : michel freiha <michofr at gmail.com>
? : Asterisk Users Mailing List - Non-Commercial Discussion <asterisk-users
at lists.digium.com>; asterisk-users-bounces at lists.digium.com
Envoy? le : Lundi, 15 D?cembre 2008, 21h35mn 01s
Objet : [asterisk-users] tcpdum
Dear All,
I run the below tcp dump on my asterisk server
tcpdump -i eth0 -n -s0 -v udp port 5060
I got the following result
20:29:48.596867 IP (tos 0x10, ttl 64, id 0, offset 0, flags [DF], proto 17,
length: 373) SIP_PROXY_IP.5060 > Asterisk_IP.5060: UDP, length 345
What i need to know please what TTL means specifically and what is the best
value og TTL and what is the lengh vale mean
Regards
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Am Montag, den 15.12.2008, 22:35 +0200 schrieb michel freiha:> Dear All, > I run the below tcp dump on my asterisk server > tcpdump -i eth0 -n -s0 -v udp port 5060 > I got the following result > 20:29:48.596867 IP (tos 0x10, ttl 64, id 0, offset 0, flags [DF], proto 17, length: 373) SIP_PROXY_IP.5060 > Asterisk_IP.5060: UDP, length 345 > What i need to know please what TTL means specifically and what is the > best value og TTL and what is the lengh vale meanEvery time a TCP/IP packet travels through a router, the router substracts 1 from the TTL (time-to-live) field. The packet is discarded by the router when TTL reaches 0. This ensures a packet not to go bouncing eternally in a misconfigured routers topology. Also, is used in mesauring distances between network segments (man traceroute). Learn a bit of the commands traceroute and mtr. If you can't get any communication to very distant segments and mtr detects that, then you can play with iptables and the TTL field. otherwise, DON'T!!! The length field: the first one is the total packet size and the last is the user data contained size. Anyway, tcpdump is not very accurate in measuring UDP sizes, i mean it could make some mistakes. UDP packets travels in a connectionless environment; on the contrary, TCP establish a connection, that forces to verify that every packet reaches its destiny; udp packets are meant to be sent once and not verified. Other layers (normally layer 7, application) verify packets arrival. Good luck! -- Rodolfo Alcazar Responsable red y datos Deutsche Gesellschaft f?r Technische Zusammenarbeit (GTZ) GmbH Programa de Apoyo a la Gesti?n P?blica Descentralizada y Lucha Contra La Pobreza - PADEP Av. S?nchez Lima 2226 La Paz, Bolivia Tel: +591 22417628 (121) Fax: +591 22417628 (126) Web: www.padep.org.bo Email: rodolfo.alcazar at padep.org.bo