Windows Mobile 5.0 Sip?

Is thier a sip available that we can use with out asterisk server on a windows mobile 5.0 phone?

Dont quite get what you mean, If you mean SIP Phone for WM5 then yes there is one by SJlabs, If thats not what you mean then you will need to explain further.

Ian

sjlabs.com/sjp.html

Install this on WM5 phone, and it will be like im dialing from a phone at work correct?

Has anyone used this? Just wondering how the voice quality is via just over cellphone provider service (gsm i believe)

Xten also has a soft phone but you have to pay for it. As far as voice quality it depends on your netwrok speeds and your latency. I have tried VOIP over EVDO and it worked. I cont know the speeds of GSM so I cant say for sure. The best thing would be is to test and see what happens. Also if you use g729 it may be easier on the bandwith.

voip over evdo should work decently well. GSM/GPRS will probably need G.729 or iLBC as it tops out at around 35kbit/sec. GPRS also has high latency- around 800ms as I recall, which will create a noticable delay on your call audio. GSM/EDGE should work wtih GSM or maybe g726-32, but you won’t be able to use g.711 ulaw unless you have UMTS (3g).

I recommend a lower-bitrate codec like GSM or g726-32. G729 or iLBC will work better if you have a slower link, but they require more CPU to encode which might eat up your battery faster.

You should also investigate your carrier’s policies as far as data usage. Many carriers have contract provisions that disallow voip service or discourage heavy usage with vague ideas like they reserve the right to restrict service to anybody that creates an ‘unusually large burden’ on the network.
These provisions are enforced more or less depending on your carrier. In the USA for example, Verizon Wireless is aggressive and has killed a lot of mobile broadband (evdo) accounts for ‘excessive usage’.

Damn. There go my hopes of using VOIP out of my car. Do you think they know about port 4569 yet ? :wink:

well remember prohibiting it and blocking it are different. I know at least one or two carriers block it (not sure which ones offhand or how they block it). I’d assume they just drop all port 5060 traffic which can be worked around by changing the SIP port, same with iax2, just change port 4569 to port 80/443/whatever.

Alternatively you can use a VPN, that will get around anything they have going. An easy way to set this up is get a Linksys WRT54GL router and a copy of the ddwrt firmware, then set up the PPTP server on it. I believe Windows Mobile supports PPTP, which means you can securely tunnel back to your home netowrk and thus your * server.
Note that some carriers I think block PPTP unless you get the ‘business’ plan, I know tmobile used to but i dont think they do anymore.

The other problem though is that VoIP isn’t nearly as efficient with BW usage as cellular voice. It gets close if you use a codec like GSM but it’s still worse because there is a LOT more overhead. Also keep in mind VoIP may be more senitive to low signal strength or fringe coverage areas than normal cellular…

Another thing that may work equally well cost wise- a few carriers (Tmobile, alltel that i know of) have a ‘calling circle’ plan where you can call like 4 or 5 people as much as you want without even paying minutes. Make your * server one of these…