3G Router for VOIP

Hi Fellas

I need to purchase a 3G router that works seamlessly with VOIP.
Currently using this.

We can make calls. Calls are brilliant. Quality is exceptionally good. However we cannot receive calls. When the person dials they receive a message stating the person is unavailable. When you pickup the ringing handset you hear nothing.

The provider tells me its the 3G router thats causing trouble. So which router can I purchase?

I can purchase the HUAWEI B683 , but surely not such an expensive router is required just to receive the call on the handset.

Is this perhaps a common VOIP problem?

This sounds more like a codec issue or a NAT problem.

The provider reckons the routers NAT is the problem. I would just like to know who here has successfully used VOIP over 3G and what router they used.

Unless you are with Vodacom and activate the unrestricted APN chances are the inbound requests are being blocked on the normal Internet APN

Hi Peon,

Lets see if we can get to the bottom of this, I checked the link to the router you are using, I don’t know this thing but it should be ok.

Firstly it would help to know which carrier you are connected to MTN, Voda ect, and what you are running behind the router, PBX, IP phone / Phones ect ?

Here are a few tips to steer you in the right direction, download a free soft phone and load your account details, have your 3g stick in the PC ( so bypass the router) pls be aware that these free soft phones do not drive g729 codec so make sure you provider has enabled g711. Test inbound and outbound, this will clear up any APN issues, I think that 8-ta now comes standard with unrestricted APN. If this works OK, you have NAT issues ! The codec must be ok because you are negotiating it with the provider with outbound calls. If we prove it to this point, ill dig in and give you details how to set up the router. SIP is a 2 layer protocol and the set up and tear down of calls is done on 1 layer (port 5060 normally) while the media ( RTP voice stream) is handled on a different layer, this is why although the call is set up, the media stream is blocked.

An interesting point is that I set up a small home office for my wife, VoIP over Cell C stick and did not even invest in a 3g router for her ! The set up is simple, a basic 4 port old Telkom router acting as a switch, (it chucks out IP addresses via DHCP) free SIP server on the PC and the cell C stick plugged into the PC, IP phones on the LAN. This works very well ! The servers you can use are, 3CX, Snom 1, BizPBX ect, they are all free to use in a small environment but only the ‘paid versions support g729 so things could get a little bandwidth hungry if you are making a lot of calls on g711. They do support GSM and im about to do some tests with that. The BizPBX can take a standard g729 codec without upgrading to the full version !
The reason I like this set up is you get all the bells and whistles of a PBX for free !

Requirements to set this up are ? If you could get a job at McDonalds as a chef, you should be able to handle it

Hope this helps

Thanks Paul

Using Vodacom. Im going to apply for an unrestricted APN and test that. Fail that Im going to get a Tenda 3G router. Ive had quite alot of joy with them.

Fail all of this im going to try what you mentioned here. I will also bring one phone with me to test over ADSL.

Cant wait for the week to start to work at this again.

I am the provider and from my side I am seeing registrations with sessions becoming unreachable within a few seconds thereafter. Problems also on inbound calls where the session seems to break after the 180 ringing. I'm pretty confident that there is a firewalling or NAT issue here because the session opens and then times out very quickly. It is possible that the issue may be due to the Vodacom APN restrictions (i.e. firewalling on their side) or nasty NAT code on the router (Planets are not the best). My suggestions were to pick up a prepaid MTN SIM for testing and to try a Billion 6200NXL router.

I'm glad to see that, by and large, the general advice is similar to mine.

For clarity, there is no codec issue here. Codec issue would show a 488 or 603 on the SIP trace and we definitely didn't get that. We're getting sessions timing out.

MTU may be an issue, but it seems extremely unlikely give that options packets are pretty small and they're timing out too.

Im itching for the week to start so I can work on this. Ive got a sneaky suspicion its the APN. Buying a new router tomorrow anyway.

So now you have it from the horses mouth ! As you say the 3g is Vodacom i can tell you this, i have tested Vodacom 3g (prepaid) on Switchtel a couple of months ago using g711 (which Switchtel enabled) worked fine, so unless there is a difference in APN settings between Vodacom prepaid and contract, its down to NAT in the router as most of us here have suspected.

paulcolmer said:

So now you have it from the horses mouth ! As you say the 3g is Vodacom i can tell you this, i have tested Vodacom 3g (prepaid) on Switchtel a couple of months ago using g711 (which Switchtel enabled) worked fine, so unless there is a difference in APN settings between Vodacom prepaid and contract, its down to NAT in the router as most of us here have suspected.

Click to expand...

Agreed, im going to buy a Billion tomorrow and a Tenda. If you read my first post, I enquired as to which routers you fellas might have used.

TP-Link MR3020?

Victory!

On monday replaced old equipment with new Billion router and Vkom 3G stick. Still didnt work.

Replaced sim in Modem with MTN one. WORKS!

Must be the Vodacom APN. Applied successfully for an unrestricted APN -> Victory!!!!


So moral of the story. If you using Vodacom and having routing issues and dwang, get the unrestricted APN.

Peon said:

So moral of the story. If you using Vodacom and having routing issues and dwang, get the unrestricted APN.

Click to expand...

As I suspected

Followup, problem still persists, in fact even worse.

Testing the handsets on ADSL produces perfect service. Every call is made and calls are received. The problem is Vodacom defined.

Ive tested with a contract sim, same deal. Outgoing calls dont work.

Ive logged a fault on Monday and finally today can reveal what I was told by Vodacom team leader.

According to Curtis Green form Vodacom Midrand - VOip is not supported on the Vodacom network.

VodacomData who is on the forum, please comment as you have been invited to this topic.

Does general internet access still work over Vodacom? i.e. there's not some issue with your tower?

General internet screams. Download at about 3Mbps and upload at 2Mbps. General internet is flawless.

Peon said:

Followup, problem still persists, in fact even worse.

Testing the handsets on ADSL produces perfect service. Every call is made and calls are received. The problem is Vodacom defined.

Ive tested with a contract sim, same deal. Outgoing calls dont work.

Ive logged a fault on Monday and finally today can reveal what I was told by Vodacom team leader.

According to Curtis Green form Vodacom Midrand - VOip is not supported on the Vodacom network.

VodacomData who is on the forum, please comment as you have been invited to this topic.

Click to expand...

Hi Peon

Let's start with your number , kindly send that to me and i will check your SIM profile along with the BTS you are connecting to.

VodacomData said:

Hi Peon

Let's start with your number , kindly send that to me and i will check your SIM profile along with the BTS you are connecting to.

Click to expand...

VD,

Get as much detail so we can let Engineering trace. The Unrestricted APN should have resolved all of this from our side. Copy me in on the mails and I'll track it as well.

Peon said:

General internet screams. Download at about 3Mbps and upload at 2Mbps. General internet is flawless.

Click to expand...

That's odd. Your problem currently doesn't sound like NAT anymore as in the past only inbound calls were affected?

VodacomData said:

Hi Peon

Let's start with your number , kindly send that to me and i will check your SIM profile along with the BTS you are connecting to.

Click to expand...

jannievanzyl said:

VD,

Get as much detail so we can let Engineering trace. The Unrestricted APN should have resolved all of this from our side. Copy me in on the mails and I'll track it as well.

Click to expand...

But the big boys are on it, so I'm sure they'll get to the bottom of it.

I have sent my details, any assistance would be appreciated. Im sure this would be beneficial for other industry members.

Thank you.