Help sought with config for BT SIP Trunk (Hipcom/Broadworks) and Cisco SBC/CUBE and/or Call Manager Express

[Mike Tubby]

Does anyone have a working configuration for a BT SIP Trunk being used with a Cisco Session Border Controller (Cisco Unified Border Element)?

I want to port our work phone system on to BT SIP Trunk and have been given the 0560........ Trunk Group Number and a password and not much else.

I have a Cisco 2811 with CUBE/SBC on it (Advanced Enterprise 15.1(4)M9 ) and have a built a config based on what works with other SIP providers but can't get the CUBE to register with BT. The BT trunk (was Hipcom, now Broadworks) just returns "401 Unauthorized" to everything?

BT assure me that the phone number and password I have are correct and active on the system.

I send 'REGISTER', they send '401 Unauthorized' with a 'WWW-Authenticate' header (challenge), I reply with a 'REGISTER' with an 'Authorization' digest response, they refuse with a '401 Unauthorized' ... which fails.

I have deduced that if you use an unsupported User-Agent they return "403 Forbidden", I have deduced that the username (trunk group phone number) is probably correct - if you get it wrong they return a "404 Not Found" and Q.850 clause "incorrect username".

This leaves me guessing that I have the wrong domain name, or need an authentication realm or some other magic pixie dust ...?

I note that they are sending a weird realm with the auth challenge: realm="btr.a5941729" - I can't tell if this is significant.

Alternatively, is there something 'special' about the service on uk.ic.sipconnect.hipcom.co.uk -- for example does it only work if the SIP is originating from behind a firewall in what otherwise would be (potentially) 'broken' or only with 'old' Cisco IOS or something?

I've been working from the Hipcom document "Cisco Call Manager Express -
SIP Trunking - Revision 1.1", dated 2010 ... this most likely expects an *older* version of Cisco IOS than I am running.

Any help appreciated. Beer for the first person to fix it ;-)

Regards


Mike Tubby MJT4-RIPE

[R. Mark Clayton]

SIP trunk? Who sold you those?

http://www.voipfone.co.uk/PB_sip_trunks.php
"SIP trunks are totally imaginary products dreamt up by the telecommunication industry as a way of charging you and providing nothing "


Incidentally BT SIP is very temperamental. Ours only works when there is a PC running with a their softphone connected on it, however 99% of the time that number is only used for incoming.

[Mike Tubby]

I agree - "SIP trunks" are sort-of-made-up but for £7.95/trunk/month I get 5000 mins of landline and 500 mins of mobile. With four of these "trunks" in a bundle I send up with 20,000 mins of landline and 2000 mins of mobile calls...

... if I can get it to work :-)

Mike

[R. Mark Clayton]

Here is what I use with BT: -


Personal Provider Data

Authentication Name: 0560nnnnnnn
Authentication password: XXXXXXX
Username: 0560nnnnnnn
Display name: <whatever you like>










Hide Advanced Settings





General Provider Data

Domain: bmnhb-02.bt.com
Proxy server address: sip.bbvservice.nat.bt.com
Proxy server port: 5060
Registrar server: sip.bbvservice.nat.bt.com
Registrar server port: 5060
Registration refresh time: 60 sec

Network

STUN enabled: Yes NO
STUN server:
STUN port: 3478
STUN refresh time: 240 sec
NAT refresh time: 20 sec
Outbound proxy mode: Always AUTO Never
Outbound proxy: www.bbvservice-560313.bt.com
Outbound proxy port: 5060


The password had to be picked out of the page used to set up the softphone on the PC. BT are as helpful as...

[Graham.]

Sip Trunk packages aside, I wouldn't want to use the 056 number range
for incoming calls, simply because of public perception of how much or
little they cost to dial, and that 01905 or any other STD code you
might want can be had for free.


--

Graham.

%Profound_observation%

[R. Mark Clayton]

I don't the account has a geographic number (0161 341 nnnn), however for registration purposes it is the underlying virtual number BT uses to do this.

You can call that number too and for Voipfone call the SIP number either 0161446xxxx@179... or 0560xxxxxxx@179... (sorry not got their fixed IP address to hand).

>
>
> --
>
> Graham.
>
> %Profound_observation%

[Graham.]

Yes, I was aware that Voipfone gives you an 056 by default, and they
can sell you a geo, or port one in. I didn't know they reccomend using
the IP address, I always set them up to sip.voipfone.net which I see
resolves to 195.187.173.27 and, unusualy, blocks ICMP pings.

--

Graham.

%Profound_observation%

[R. Mark Clayton]

When I receive SIP calls on my mobile they appear as <number>@195.187.173.27 and I can call them back. Can't do an @ symbol on my phones, although I suppose I could try it from Zoiper.

You can also call from account to account within Voipfone for nothing by using the account number (usually 301nnnnn).

>
> --
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> Graham.
>
> %Profound_observation%

[Mike Tubby]

On Thursday, 10 December 2015 18:09:23 UTC, Mike Tubby wrote:

Okay, I've finally sussed it...

BT SIP Trunk is contracted out to Hipcom (was Hipcom and now Broadsoft/Broadworks since they, in turn, purchased Hipcom) and the platform has a foible in its configuration...

You have to send the initial registration to 44560...@sipconnect.hipcom.co.uk and then when you get the WWW-Authenticate challenge re-send the REGISTER in digest mode using 0560nnnnnn as the username!

After which you get registered okay - yay!

The 0560nnnnnn number is the "Trunk Pilot" you're not really expected to accept calls on this number - but you can. Your real calls come via the number(s) that you have "ported in" to the BT SIP Trunk service - in my case 01905xxxxxx.

BT Business SIP Trunk appears to be locked down to support a limited range of "approved" PBX's according to what is in the "User-Agent:" string when the REGISTER is sent. A User-Agent sessing of "My Little Pony" gets a "403 Forbidden" response on REGISTER :-( as would Asterisk.

Now, I could fake the headers to something like "User-Agent: IP Office 9.0.4.0 build 965" which would let me in or pretend to be a Session Border Controller like "User-Agent: Cisco-SIPGateway/IOS-12.x", but what I decided to do was to implement a real Cisco Unified Border Element (CUBE) i.e. a Sessionn Border Controller on a Cisco 2811 router I had lying around spare.

The 2811 operating as a CUBE/SBC is really just a SIP application-layer proxy - it registers with the BT SIP Trunk and has a "trusted" relationship with both the BT SIP trunk and with my Asterisk PBX... The SBC implements toll-fraud prevention and screens incoming SIP then forwards valid hosts/INVITE/number combination numbers to my Asterisk PBX.

The SBC is also able to perform codec translation although initial testing suggests that G711-alaw is used universally and hence translations aren't really needed, however I have not yet tested calls from mobiles.

So, I now have it working and can connect an "unapproved" PBX to a BT Buiness SIP trunk by way of a Cisco CUBE/SBC.

Happy times ;-)

Mike

[Graham J]

Mike Tubby wrote:
> On Thursday, 10 December 2015 18:09:23 UTC, Mike Tubby wrote:
>> Does anyone have a working configuration for a BT SIP Trunk being used with a Cisco Session Border Controller (Cisco Unified Border Element)?
>>

[snip]

OK you seem to be quite knowledgeable ...

Do you know anything about the Gigaset T500 used with DE410 IP Pro
handsets? The manuals I have are either wrong or simply omit
information I need.

TIA

--
Graham J

[R. Mark Clayton]

I think this might explain why my Gigaset box will only register / make calls when the "approved" BT Softphone is active.