[cisco-voip] CCM SIP connection to B2B getting fast busy

Fri Mar 5 00:29:09 EST 2010

Hi Nick,

My apologies for the confusion.

Let me ellaborate further the diagram and description as i came to
understand it further from time to time asking the provider.

ip phone(skinny)---CCM7------SBC-------Huawei proxy server.

The SBC suppose to be the one to control over the signaling and usually also
the media streams involved in setting up the communication. Our CCM does
have ip connectivity to the SBC only and not the huawei device. Shouldn't it
act like a CUBE so we don't need connectivity to the public.

Regarding the sip invite, i was refering to the initial SIP INVITE requests
sent by the CCM7 via sip trunk since the call came from 7961 ip phones
registered using SCCP on CCM7. The 7961 phone calls out. CCM7 suppose to
initiate SIP invite request to the configured ip address(SBC ip) on the sip
trunk.

If trunk is configured to point to the CUBE(cisco router 10.10.10.2) then i
sniff the packet on the CCM(10.10.10.1). The sniffer trace has 10.10.10.1
Source address - 10.10.10.2 Destination address SIP invite.

If however the trunk is configured to point to the SBC directly, i see no
SIP invite request initiated by the Callmanager on the sniffer trace and
also the provider claims that he is not seeing any request comming from the
CCM7 on their SBC.

If the SBC or huawie does support only UDP, shouldn't i suppose to see SIP
invite request via  UDP porton the sniffer trace generated by the CCM? In
the case CCM7 trunking directly to SBC without CUBE, i see no sip invite
requested when cisco ip phones tried to make outgoing calls.

I hope this clarifies the confusion.

thanks,
Jeff

On Thu, Mar 4, 2010 at 10:52 PM, Nick Matthews <matthnick at gmail.com> wrote:

> I'm still confused on what you mean by no SIP invite.
>
> It's possible that the huawei only supports UDP SIP and it's not
> completing the 3 way TCP handshake.  You can change that under the SIP
> profiles to be UDP only.
>
> Otherwise, check that huawei has routing back to the IP of your CUCM,
> and firewalls aren't involved.
>
> -nick
>
> On Thu, Mar 4, 2010 at 3:38 AM, Jefflin Choi <jefflin.choi at gmail.com>
> wrote:
> > Hi,
> >
> > Thanks for all the reply.
> >
> > Tried placing the a CUBE in the middle and seems like there is already
> SIP
> > invite being sent. Too bad the huawei isn't full configured yet to
> determine
> > if all is ok.
> >
> > I was wondering....I tried to make a test call using SIP trunk directly
> to
> > the B2B SBC and no sip invite. But i did get sip invite when i pointed it
> to
> > the cube.
> > All i can see on the sniff trace from CCM to B2B is:
> > TCP 35472 > sip [SYN] seq=0 Win 5840 Len=0 MSS=1460 TSV=82731827 TSER=0
> WS=2
> >
> > In fact i just changed the ip of the CUBE to the B2B SBC to make sure
> > configs are exactly the same but no sip invite unlike when it is pointed
> to
> > the CUBE. Is this normal? Any thoughts?
> >
> > Thanks,
> > Jeff
> >
> >
> >
> > On Thu, Mar 4, 2010 at 1:10 AM, Mark Holloway <mh at markholloway.com>
> wrote:
> >>
> >> You most certainly need CUBE.  You can find the CUBE guide for
> sip-to-sip
> >> here.
> >>
> >>
> http://www.cisco.com/en/US/docs/ios/voice/cube/configuration/guide/vb-gw-sipsip.html
> >>
> >>
> >> On Mar 3, 2010, at 7:18 AM, Jefflin Choi wrote:
> >>
> >> I see. So a router in the middle is required then. Doesn't the CCM7
> >> support it without the CUBE?
> >>
> >> Thanks.
> >>
> >> On Wed, Mar 3, 2010 at 9:48 PM, Dennis Heim <Dennis.Heim at cdw.com>
> wrote:
> >>>
> >>> You will probably end up having to use CUBE, instead of terminating the
> >>> trunk to CCM.
> >>>
> >>>
> >>>
> >>> Dennis Heim
> >>> Network Voice Engineer
> >>> CDW  Advanced Technology Services
> >>> 11711 N. Meridian Street, Suite 225
> >>> Carmel, IN  46032
> >>>
> >>> 317.569.4255 Office
> >>> 317.569.4201 Fax
> >>> 317.694.6070 Cell
> >>>
> >>> dennis.heim at cdw.com
> >>> www.berbee.com
> >>>
> >>>
> >>>
> >>> From: cisco-voip-bounces at puck.nether.net
> >>> [mailto:cisco-voip-bounces at puck.nether.net] On Behalf Of Jefflin Choi
> >>> Sent: Wednesday, March 03, 2010 8:31 AM
> >>> To: cisco-voip at puck.nether.net
> >>> Subject: [cisco-voip] CCM SIP connection to B2B getting fast busy
> >>>
> >>>
> >>>
> >>> Hi,
> >>>
> >>> I'm trying to configure a SIP connection to a 3rd party B2B SIP device,
> >>> then B2B will relay to a Huawei (SIP) device on the other end.
> >>> topology:
> >>> IP Phones ------CCM7 -------(provider)--B2B---------Huawei---pstn
> >>>
> >>> configuration:
> >>> CCM is configured with SIP trunk with ip address of the B2B and route
> >>> pattern uses the SIP trunk configured.  MTP required uncheck as of the
> >>> moment.  codec G711uLaw and No authentication required.
> >>>
> >>> Problem:
> >>> Outgoing call from IP Phone to PSTN gets fast busy signal.  When placed
> a
> >>> sniffer in between CCM7 and B2B gateway, i didnt see any sip invite
> >>> initiated by the CCM7. CCM7 and ip phones only have traffic
> reachability to
> >>> B2B but not Huawei.
> >>> The provider (B2B to pstn) was tested using altitude(as claimed by the
> >>> customer) and works fine but we are testing using CCM7.
> >>>
> >>> Question:
> >>> 1> Am i right to use CCM trunk to connect to the B2B sip?
> >>> 2> Any additional configs i need to configure? Misconfiguration?
> >>> 3>Should i expect SIP invite to be sent by CCM when call is triggered
> by
> >>> ip phones?
> >>>
> >>> Thanks,
> >>> Jeff
> >>
> >> _______________________________________________
> >> cisco-voip mailing list
> >> cisco-voip at puck.nether.net
> >> https://puck.nether.net/mailman/listinfo/cisco-voip
> >>
> >
> >
> > _______________________________________________
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> >
> >
>
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