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Community Member

SIP and HOSTS file!

Hi,

Here in the UK, BT's (British Telecom) SIP service is tightly configured to their own hardware and they won't tell you how to set up SIP accounts on other hardware. If you know where to look, then you can get the required details and set up the SIP accounts on other hardware.

Now I've done this before and I have various softphones that happily register to my BT SIP service - so I know my settings are correct and work!

The problem is that BT are sneaky with regard to the SIP Registrar server and don't publicly advertise the server name, so a DNS lookup always fails. I'm not sure what they do in their own hardware, but for other hardware, the simplest solution is a to add an entry to the local hosts file, to resolve the registrar address locally.

With the UC320W, it is so tightly locked down, that I cannot get in to add the required entry to the HOSTS file and the Network options on the configuration panels are extremely limited.

Is there any way of getting the HOSTS file updated (maybe a PMF could be created?) to add the entry:

62.239.15.132   bmnhb-02.bt.com

Note, I cannot just use the IP address in the Registrar/Proxy field, it has to be the name - that's how difficult BT they try and make it!

Thanks

Clive

2 REPLIES
Community Member

Re: SIP and HOSTS file!

I've managed to 'work around' this problem, by installing a DNS server on one of the network machines, with an entry for  bmnhb-02.bt.com and adding the local machine as the secondary DNS server on the UC320W WAN configuration.

The BT SIP account now registers and inbound and outbound calls all seem to work just fine.

But I would still rather have the solution directly in the UC320W - ie an updated HOSTS file, rather than relying on a local machine being available!

Bronze

Re: SIP and HOSTS file!

Hi Clive - Stepping back a bit, what happens if you include your SP's host names in the realm/proxy fields, but use the IP address as the outbound proxy?

Anyway, using fixed IP addresses is a short term solution as at some point they will change.

DNS is used extensivly within voice networks for load balancing and redundancy

For example, over here at VoIP - we have two machines running proxy.voip.co.uk - look:

C:\Users\nslookup

> set type=srv

> _sip._udp.proxy.voip.co.uk


_sip._udp.proxy.voip.co.uk      SRV service location:
          priority       = 0
          weight         = 0
          port           = 6060
          svr hostname   = sbc5.a.synergy.voip.co.uk
_sip._udp.proxy.voip.co.uk      SRV service location:
          priority       = 0
          weight         = 0
         port           = 6060
          svr hostname   = sbc5.b.synergy.voip.co.uk

voip.co.uk      nameserver = a.ns.voip.co.uk
voip.co.uk      nameserver = b.ns.voip.co.uk
voip.co.uk      nameserver = ns0.ncuk.net
a.ns.voip.co.uk internet address = 80.249.108.54
b.ns.voip.co.uk internet address = 193.203.210.54
> set type=a
>
> sbc5.a.synergy.voip.co.uk
Non-authoritative answer:
Name:    sbc5.a.synergy.voip.co.uk
Address:  193.203.210.29

> sbc5.b.synergy.voip.co.uk
Non-authoritative answer:
Name:    sbc5.b.synergy.voip.co.uk
Address:  193.203.210.39

>

We also have another machine service proxy.voip, for systems that don't support DNS SRV

> proxy.voip.co.uk

Name:    proxy.voip.co.uk
Address:  193.203.210.38

>

Adam

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