Grandstream GXP2000 and OBi100

[Brian01]

Is there any way to add some security to this?

I wanted to use the Obi110 to call out on Google Voice from an Android Gingerbread phone using the native SIP stack.  (not the obion app)  The instructions here worked just fine.

However, if I have ports 5060-5061 open to the internet, then anyone can use my obi to call out if they can discover the username.

Is there any way to add authentication?  Is the username passed in the open?

[Stewart]

Is there any way to add authentication?  Is the username passed in the open?

I don't believe there is any way to make this really secure.

You can get pretty good protection from random attacks by using an obscure port (not 5060 or 5061) and a long pseudo-random user name.  However, that won't protect you from someone who can capture your traffic (unlikely over 3G, but certainly possible over open or WEP Wi-Fi).

If you are using this for domestic calling, you could set up the OBi to permit only specific area codes when bridging.  If calling internationally, GV rates are not very aggressive -- I'd just use a regular SIP provider instead.

[Dale]

Is there any way to add some security to this?

I wanted to use the Obi110 to call out on Google Voice from an Android Gingerbread phone using the native SIP stack.  (not the obion app)  The instructions here worked just fine.

Brian, can you point to the instructions? All I could find was a thread saying that it was not possible: http://www.obitalk.com/forum/index.php?topic=205.msg930#msg930

[Brian01]

OK, I posted my Android config in that thread:
http://www.obitalk.com/forum/index.php?topic=205.msg10762#msg10762

Regarding security, I noticed from above that you can use X_AccessList to limit access by ip address.  That's something, anyways.

Thanks everyone for the info.

[Dale]

Thanks Brian, yes I saw them there.

If one has a domain name pointing to one's home network, I suspect one could in fact set it up to access your Obi even when not at home...

something like this:

Obi at fixed IP address 192.168.1.200
Some domain name pointing you your home router (such as from no-ip.com)
Eg myzootyname.com
Home router set to direct incoming traffic on port 5066 to the obi.

then the Obi is essentially at myzootyname.com:5066

now one issue I see is that when we are away from home but on a wifi network, making a phone call will use the home network twice - voice data would go from the phone to the router to the OBi and then out through the router again to the end point. Depending on the speed of the home network connection this may be no problem.

This would mean that one can use it when away from home.

I am also interested in using the native Nexus S stack so that I get fill contact list integration etc. (I did import my contact list into the Obion app but contact changes wont sync up I am sure.

[Brian01]

Yeah. You could use the ip address of your home, no need for a domain.

It's also a one line hack of the Android system to make the native sip stack work over cell data in addition to wifi.  So you could conceivably use the setup over your cell carrier's 3g or 4g for free cell calling.  (wouldn't try it over EDGE)

As you say though, the quality would depend on your home connection, cell tower, etc.  I've tried VOIP over T-mobile 3g and it works just fine if you're near a nice strong data node.

What I really want is a better dialer.  Right now I use the built-in dialer and it asks if I want to use Google Voice or not...then it asks if I want to use cell or internet...two annoying dialogue boxes.  We need a dialer with checkboxes and a better default system.

[Dale]

yes but the IP address of the home router can change and the no-ip DNS entry ensure that it can be found....

I told my android google voice never to dial calls... GV actually uses the cell connection to call into GV and then bridges that to the call you dialed. So for a T-mobile pay as you go customer it achieves nothing.

[skyviewelectronics]

I have successfully set up Google Voice on SP1 and am trying to connect my Grandstream GXP2000 to SP2.  I followed the instructions in this article:

http://voxilla.com/2011/02/15/how-to-obify-your-ip-phone-no-asterisk-involved-2623

However, the details for registering the Cisco phone don't really apply to the Grandstream phone, which is not registering with the OBi100. Can anyone provide guidance that is specific to a Grandstream phone?

Thanks so much for the link!

I used that great guide to set up a few Grandstream GXP2140's with an Obi202. The problem I'm having is transferring calls between phones. All of the phones have EXACT identical settings (except for the IP address).

If a call comes in and I pick it up on one GXP2140 and I want to transfer it to another GXP2140 how can I do it? I tried using Quick IP dialing, but that doesn't support call transfer (just disconnects the originating call).

I asked in Grandstream support chat, but they weren't familiar with this freaky Obi setup "Didn't you just set up your voip providers settings inside the GXP2140??".... "Ummm, no. Because Anveo limits me to two devices logged in, so using my Obi box as the proxy I can have tons of phones all use Anveo..." so they had no idea how call transfer would work. Any ideas??

Another thing that's freaky. I figured if I set up identical settings in each phone, that the "lines" would be shared on each phone (i.e. if I was on a call on phone1 line1, then on phone2, line one would be lit up red, or at least let me barge into it), but nope. If a call comes in on "line 1" and I put it on hold, I can click "line 1" on the other phone, and I get a dialtone, and can make calls no problem!! strange

If you have any information on how I can transfer a call from one IP phone to another one logged into the same Obi box please let me know.

-Jamie M.