3G Router for VOIP

Just got a call from someone at Vodacom. Half asleep and didnt know whats going on.

Not looking good.
VodacomData, do you have anything to report?

EDIT: I cant telnet into our VOIP provider, i can reach Vodacom's VOIP address.


Vodacom, can you please give a definite answer as to if you allow VOIP on your network or not.
 
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On your Billion Router under firewall uncheck the setting SIP ALG, depending on the router you may have a dedicated ALG section. turn it off, this can cause alot of problems. I recommend the Billion 7800 router, it takes a sim card directly into the router, i have many of these in the field with unrestricted APN and they work very well.

Thanks
 
Setting has been disabled. Vodacom firewall blocking connections on port 5060 to my SIP provider.

I wish companies didnt resort to these measures.
 
This is surprising. We have hundreds of users connecting to us over 3G with Vodacom...without problems.

Are you sure this is the case? What does your provider say about this?
 
We had a conference call today with 4 people involved. The SIP provider joined in as well for a bit. I was on site on the phone as they cross-checked trace logs on their side as VOIP calls were made or attempted to be made.

It appears it is not intentional. But critical packets needed by the SIP gateway to auth are dropping for some reason. This appears to have Vodacom a bit stumped. Tomorrow morning at 9 another conference call.

I must commend Vodacom and our VOIP provider. Its very easy to get snotty and irritated. Yet both parties have remained calm and professional in the face of a difficult and complicated problem.

So, lets see what happens tomorrow.
 
No solution or program found. It appears IP Datagrams are matching a pattern and being filtered. A attempt at a solution has been made. Will report accordingly.
 
Peon said:
No solution or program found. It appears IP Datagrams are matching a pattern and being filtered. A attempt at a solution has been made. Will report accordingly.
Click to expand...

Kind of defeats the purpose of unrestricted?
 
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I cant help but agree Morkhans. But its both ways, in and out. It appears with a different handset you can better control the G729 session. Preliminary tests show that this session is not filtered. I adjusted payload length from 20ms to 30ms and it seems to be working. Need to use it for about a week.

Vodacom still needs to figure out what pattern is filtering the packets. This is between Vodacom and the SIP provider. I stand at the coalface. My client doesnt care about reasons and good intentions, just demands results.

So YeaLink phone causes the bug where as a default Atcom works. Will reset YeaLink to default and post results. The yealinks I received pre-programmed.
 
i tried with the 'standard' Huawei B970, and couldnt understand why its not working for VOIP... Skype, MSN calls work fine, so assume VOIP packets are different.
I thought it could be the apn, as it was the standard "internet" APN, (Vodacom and MTN)
somehow i tried a USB modem with the softphone app on its own, and voila voice worked fine... so i figured it must be something on the B970... NAT or some other setting.
Even tried with the Netgear MBR1200, as its also an excellent 3G router... but same issue, i can dial out, and hear the other side, but they cant hear me.
Cant see anywhere in the settings to add/enable/disable to make it work
Tried the cheapy ZyXEL NBG4115, with a usb modem plugged into it.... IT WORKS! (even on standard 'internet' APN)
Its not the best of 3G routers IMO (guess thats what u pay for), wifi can be a little stuborn, but as long as it works for VOIP, all i need.... guess, being cheap its quite simple and doesnt have all the complicated settings, that just.... complicate stuff :-)
http://www.zyxel.com/products_services/nbg4115.shtml?t=p

btw ... using MWEB Webcall and these cheapy USB phones u get at IC, or for much better performance, the Yealink SIP-T20P
 
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CeeBee, keep using it for a while and get above 95% calls to work. In and out. I found I could only get acceptable levels of service by unplugging the YeaLink phones and using the Atcom phones.

Bless the guys at Vodacom. They really tried their best but couldnt figure out what the problem was. They toiled hard but couldnt figure it out. Something is happening on Vodacom's network and they dont know what it is.

They cant identify what IP datagrams are causing the issue and more importantly they dont know why.

Ive exhausted myself on this problem and can go no more. Credit to the SIP provider, they've remained calm but are totally gatvol of me now.
 
Peon, did you ever get to the bottom of this?

I'm also using 3G with an IP phone, and have discovered that incoming call issues can be related to what mode the 3G router is in. In idle mode (WCDMA) if the signal is poor, the invite packets aren't responded to quick enough and the call goes to voicemail, even thought the phone sometimes rings. When the router switches to HSPA, the latency is good and all works as it should.
Really, the invites should have a longer timeout, I understand up to 32 seconds, but that's not what I'm experiencing.
 
Broadcom, the Atcom phones have worked over the YeaLink phones. I adjusted payload length from 20ms to 30ms. This seemed to work better. I have been using only 1 phone. Shortly I will add another 3 and report the results.
 
It seems that Vodacom has made another change that has blocked VoIP. All existing users that were working fine for months suddenly stopped working all at the same time. I give up with VC; I'm now just advising people to cancel their Vodacom 3G and go with any of the others (MTN/CellC/8ta).

VC are so anti-competitive in so many different manners, that this is hardly a surprise. Blocking VoIP over their 3G is the tip of the iceberg.
 
I concur, VodaCom I as a client am calling you out. You are blocking my VoIP. As I write this I have 1 of the trouble phones on my table running over adsl. Its flawless. We will not pay a single cent until you fix this.

How can you advertise being a pro South African company yet engage is childish practices, not even uncompetitive, childish.

Now the problem has widened and includes SMTP traffic. No SMTP traffic works.

I must also confess that you Advanced Data Support was lacking. Advanced Data Support could not give me a definitive answer.

Not a single cent until you send a team out to us.
 
gmza said:
It seems that Vodacom has made another change that has blocked VoIP. All existing users that were working fine for months suddenly stopped working all at the same time. I give up with VC; I'm now just advising people to cancel their Vodacom 3G and go with any of the others (MTN/CellC/8ta).

VC are so anti-competitive in so many different manners, that this is hardly a surprise. Blocking VoIP over their 3G is the tip of the iceberg.
Click to expand...

Hi gmza and Peon,

I've done some of my own investigations this evening. I used a Cell C SIM and a Vodacom SIM with a SIP client on my laptop and a SIP server on the Internet.

1) I've noticed that Vodacom is now assigning private IP addresses to me. Previously I used to be assigned a public IP address. Since I am assigned a private IP address there is a NAT router before the Internet with a SIP ALG.
2) Cell C assigns a public IP address. A SIP trace on my laptop and a SIP trace on my Internet server shows that the SIP messages are identical. So there is no modification are broken SIP ALG on their firewall.
3) On Vodacom however, the SIP ALG is modifying the SIP messages as well. The REGISTER message from my laptop is modified to include the public IP address and "102 REGISTER" becomes a "106 REGISTER". The response from my server also never reaches my laptop.

I suspect that they've installed a NAT router with a broken SIP ALG. It may not be a deliberate attempt to block SIP, or else there is no point in them sending the SIP REGISTER message to the SIP server on the Internet. Anyway, the SIP traffic on Vodacom is probably small compared to Skype, which isn't easy to block.

Peon, I suspect the same broken NAT router is affecting your SMTP traffic.

WireFree
 
Hi WireFree

In the original tests we did, registrations worked fine. The signalling was broken during call initiation (response to INVITE packet). But that being said, something changed more recently that has broken registrations as well.

Keep in mind that there is a regular APN and an unrestricted one. The unrestricted is supposed to use public IPs and not be subject to NAT, ALGs, etc. Operative word being "supposed."

But I hear what you're saying and, if that is the case, then simply moving the SIP signalling to a port other than 5060 should do the trick, so I've created a secondary port on the server side.

I don't have my Vodacom test SIM with me at the moment (it's at the office), but I'll PM Peon the new UDP port to try.

Thanks for the suggestion.
 
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gmza said:
But I hear what you're saying and, if that is the case, then simply moving the SIP signalling to a port other than 5060 should do the trick, so I've created a secondary port on the server side.
Click to expand...

Let me know how it goes. With SIP on a different port the signalling should be fine but the RTP ports may not open up on the firewall. The ALG on 5060 is responsible for opening the ports for RTP. On the unrestricted APN you should not have a problem. The only risk with the unrestricted APN, is that anyone on the public Internet can send arbitrary traffic to your IP address and you get billed for it.

WireFree
 
WireFree said:
Let me know how it goes. With SIP on a different port the signalling should be fine but the RTP ports may not open up on the firewall. The ALG on 5060 is responsible for opening the ports for RTP. On the unrestricted APN you should not have a problem. The only risk with the unrestricted APN, is that anyone on the public Internet can send arbitrary traffic to your IP address and you get billed for it.

WireFree
Click to expand...

My side is NAT friendly, so it automatically discovers when there is NAT at play and responds with the RTP to the actual (public) IP address that the SIP originates from, not to the signalled (private) IP address that the SIP signalling refers to. For this reason there is no need for an ALG.

Initial feedback is that it appears to work fine when not using port 5060, so I think you're right: it's a broken ALG. It's just strange because one of the sites affected is supposed to be on the public APN...

I'll test fully during the week when I have access to the VC SIM. Then I can also set up Wireshark on both ends and see that no packets are being dropped or meddled with!

None of this explains, however, why other non-standard ports are being blocked. E.g. Last time I tried (admittedly months ago), ViBE routers that talked happily over ADSL wouldn't play nicely over VC 3G. That's not on port 5060.
 
hi gmza, Sip connected through Vodacom 3g with my E71, can make and receive calls, don't think it is a port 5060 issue , maybe something else like firewall or nat
 
TSpeed said:
hi gmza, Sip connected through Vodacom 3g with my E71, can make and receive calls, don't think it is a port 5060 issue , maybe something else like firewall or nat
Click to expand...

Hi TSpeed,

In which town/city are you located?

WireFree
 
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