Am 14.10.2010 21:06, schrieb Tim Nelson: > > The TCP header is exactly what the NAT changes, no? > > --Tim >
to the outside yes but not inside. for example thats how a typical nat table looks like. (its from a zyxel adsl router with nat) ========================Nat session table============================== Slot Prot Int-IP :Port Out-IP :Port Ext-IP :Port Idle ======================================================================= 45 TCP 192.168.0.1 :6023 xxx :6023 zzz :44450 0 121 UDP 192.168.0.129 :5061 xxx :10619 sip1:5060 4 135 UDP 192.168.0.129 :5060 xxx :10618 sip2:5060 3 ========================Summary information============================= 192.168.0.129 is a sip phone with 2 accounts registered to sip1 and sip2. if i take a look at sip1 i will see the package from ip xxx port 10619. Ofcourse its behind nat but i will see in the contact header 192.168.0.129 port 5061. With sip ALG active also the contact header would be changed to xxx port 10619. Other way if i look on the phone i see the answer from sip1 directly as a message from sip1 port 5060 and not from xxx port 10619 or 192.168.0.1. several things wont work if you dont get the original source ip through a nat router. thats how i have learned it and see it everyday in practice. best regards stefan -- _____________________________________________________________________ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- New to Asterisk? Join us for a live introductory webinar every Thurs: http://www.asterisk.org/hello asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
