[Users] Internet Providers changing the SIP headers

Klaus Darilion klaus.mailinglists at pernau.at
Fri Aug 25 10:49:48 CEST 2006


Looks like there is an ALG (application layer gateway) between the SIP 
client and the SIP proxy. Often these SIP ALGs are broken and they make 
things bad although the are designed to help SIP over NAT.

Often this ALG are included in DSL modems (e.g. Alcatel). If this is the 
case, try to disable the "SIP-Helper" in these devices. There may also 
be a firewall at the ISP which does harm.

An often used workaround is to open an additional port at your SIP proxy 
(e.g. port 5088) and configure the SIP clients to use this port. As most 
SIP ALGs detect SIP messages simply by looking for UDP packet to port 
5060, changing the port on the SIP proxy should help.

regards
klaus

Bruno Machado wrote:
> Hi fellows.
> 
> We are in trouble with this "deceitful" error. I mean, errors. Look at 
> RURI. Our proxy receive this "thing". We have a number there! Sometimes, 
> this number is shown within the word REGISTER, like that: 
> "REGI:34846:STER". We can rewrite the URI, but Openser doesnt understand 
> the method "REGI:34846:STER". Second error: Via header. The REGISTER is 
> showing the NAT_DEVICE_IP instead UA_IP. And this VoIP isnt behind any 
> VoIP device! So, "who" are changing it? "Who" can does it? Is possible 
> that some "device" between UA and our proxy change the headers intentionaly?
> 
> This kind of problem had been happening some months ago and began at the 
> same day to VoIPs were different regions of the country (Brazil). We 
> would like to know with someone already has face it.
> 
> Thank you all.
> 
> Bruno Machado
> 
> 
> 
> U NAT_DEVICE_IP:50764 -> PROXY_IP:5060
> REGISTER :50764sip:proxy.com.br SIP/2.0
> Via: SIP/2.0/UDP NAT_DEVICE_IP:50765;branch=z9hG4bK427600003ca00000
> From: <sip:7011423 at proxy.com.br>;tag=ab510000bf39ffff
> To: <sip:7011423 at proxy.com.br>
> Contact: *
> Call-ID: 499effff9ff20000 at 192.168.1.5
> CSeq: 100 REGISTER
> Expires: 0
> User-Agent: Grandstream HT386 1.0.3.17
> Max-Forwards: 70
> Allow: INVITE,ACK,CANCEL,BYE,NOTIFY,REFER,OPTIONS,INFO,SUBSCRIBE
> Content-Length: 0
> 
> U PROXY_IP:5060 -> NAT_DEVICE_IP:50765
> SIP/2.0 407 Proxy Authentication Required
> Via: SIP/2.0/UDP NAT_DEVICE_IP:50765;branch=z9hG4bK427600003ca00000
> From: <sip:7011423 at proxy.com.br>;tag=ab510000bf39ffff
> To: 
> <sip:7011423 at proxy.com.br>;tag=22aae43fbf528d3860ded8429db379db.546f..Call-ID: 
> 499effff9ff20000 at 192.168.1.5
> CSeq: 100 REGISTER
> Proxy-Authenticate: Digest realm="proxy.com.br", 
> nonce="44edfeda1fe71fa609e7599bf2513e999e3741dd"
> Content-Length: 0
> 
> ------------------------------------------------------------------------
> Novidade no Yahoo! Mail: receba alertas de novas mensagens no seu 
> celular. Registre seu aparelho agora! 
> <http://us.rd.yahoo.com/mail/br/tagline/mobile_alerts/*http://br.mobile.yahoo.com/mailalertas/> 
> 
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> Users mailing list
> Users at openser.org
> http://openser.org/cgi-bin/mailman/listinfo/users





More information about the sr-users mailing list