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Cisco "expert" bully - need SIP 2nd opinion

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  • Cisco "expert" bully - need SIP 2nd opinion

    Hi I have a VoIp termination supplier who is a bully - well I think so because I think he has made a config error in the gateway of his Cisco and won't fix it because he won't admit it.

    The symptom is that I can make calls using the termination service but they are cut after 30 seconds. At this point it may be useful to look at the attached jpeg which to the initiated eye may answer all the questions. Its a Wireshark screenshot. I have Voipswitch at He is with Cisco at

    He says that the SIP contact is asking that the ACK responses are sent to the IP in the contact field.

    I am saying that this is being overridden by the Record-Route and my switch is sending the ACKs to the IP address defined there.

    As the shot shows my switch is sending ACKs to the address in the Record-Route part. Is this right or is this wrong? it is becuase the endpoint is not receiving the ACK we are being cut off. It is hard to get any licensed VoIp providors in Brazil so I want to persevere with this one.

    Everything I have read about his Cisco is that there are two ways - with Record-Route enabled and with it disabled. It is obviously enabled here and therefore the fact that the endpoint is not receiving the ACKs is because I am not being told to send them there - my switch is sending them to the proxy. If he were to disable Record-Route I believe it would work but I cannot for love nor money get him to even listen to my reason because he thinks that he knows it all and cannot be bothered to look into it. Or he needs to resend the ACK from his proxy. Is this right, using Record-Route is the saying that all SIP messgaes pass thought the proxy?

    I admit that I know v little SIP, but perhaps someone who knows more can understand the problem and answer this. Should ACKs go to the proxy or to the endpoint when Record-Route is enabled and does this screenshot illustrate and example of the switch sending as it is instructed in the header?

    Your help will be much appreciated.......

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