Cisco 1841 is not working properly with VOIP phone

[Chini mao]

Hi friends, recently I was trying to connect my VOIP phone ‘Polycom SoundPoint 550’ with the Cisco 1841 but however I can’t, I have try several thing to make the working of my VOIP phone, but fail to do that. So I just want to know why the connection is not working between this type of VOIP phone and with the Cisco 1841. So if you guys have any idea then please do the reply. I’m very much confused, Can anyone help me on this issue.

[shetty]

The thing that matter here for this kind of issue, is whether you Cisco 1841 router is properly managed by our ISP or not. And if you have hooked for another Cisco 1841 then, make the verification for the basic config whether they are proper or not. And check whether the connection between the VOIP phone and the Hosted Server is there or not. May be this are the things are responsible for this issue.

[Aaryan2011]

May be your Internet connection is not working properly here, so you just try to make use of this connection with some other devices for checking the internet connection is working fine or not. So for that you can connect your laptop or Desktop and try to browse Internet. If it is not working then there may be the chance that the internet connection is not there, this is one of the simple tricks to know whether the internet is working properly or not. So if you net is working fine then try to make the use of the other router and see if it works.

[Badrinath]

I Think may be your VOIP is out of range, because the VoIP provider has their own range. So if you are out of the range then this thing is possible to happen. So just try to reconnect and make use of the VOIP within the required range.

[Dalajit]

According to my suggestion you should try the best Firewall, because some of the time while you are permitting SIPS traffic outbound, maybe the SIP INVITE may carry your IP addresses publically to the SIP server. And there the SIP server will set up some of the media streams to your private IP address so for that reason there may be no reachability. So to avoid such thing there is the need for the firewall. So that the firewall NAT the IP headers and fix up the important layer used in the SIP protocol. So you should get one best firewall.

[Ebadaah28]

May be you have enable SIP ALG on Cisco 1841, so I think just verify that whether by mistake you have enabled SIP ALG? If yes then disable it. May be this will resolve this problems.
So to disable SIP ALG on Cisco 1841, use the following command

no ip nat service sip tcp port 5060
no ip nat service sip udp port 5060

[Chini mao]

Hey you are right, i have disable the SIP ALG on my Cisco 1841 with the help of those command. and it works fine. Thanks for the needful information.

[JoanaJhon]

According to my information you must try to changes the position of the router. If needed then replaced all of the micro-filters. And see whether the incoming calls working correctly or not, and there may be the chances that the problems are there at the Telephone Exchange. So make sure for this issue from the Telephone Exchange to resolve this issue.