Cisco CUBE connection to Skype via SIP

[dwaters]

Hi,

We have a Cisco 2801 running “c2801-ipvoice_ivs-mz.151-3.T2.bin”

We are trying to register to the Skype service using a Cisco CUBE, however so far no luck.

One question I do have is with regards to how NAT plays a part in this process? Do ports need to be opened inbound?

I can ping sip.skype.com fine.

Any suggestions would be great; two show commands below:

CUBE#show sip-ua register status

Line                             peer       expires(sec) registered P-Associ-URI

================================ ========== ============ ========== ============

9905100XXXXXXX                   -1         141         no

CUBE#

CUBE#show run | begin sip-ua

sip-ua

credentials username 9905100XXXXXXX password 7 XXXXXXXXXXXX realm sip.skype.com

authentication username 9905100XXXXXX password 7 XXXXXXXXXXX realm sip.skype.com

no remote-party-id

retry invite 2

retry register 10

timers connect 100

mwi-server dns:sip.skype.com expires 3600 port 5060 transport udp unsolicited

registrar dns:sip.skype.com expires 3600

sip-server dns:sip.skype.com

connection-reuse

host-registrar

handle-replaces

!

Debugs are available upon request.

Thank you in advanced, Daniel.

[Daniele Giordano · Accepted solution]

Try the command "debug ccsip messages" and post the output.

In working scenario, your cube should send a SIP REGISTER without authentication and get a 401 Unauthorized message.

After this the cube should send a SIP REGISTER with authentication.

If the REGISTER contains your local ip address, so Skype doesn't know how to respond.

In this case we will observ only REGISTER messages without answer.

We will check the top VIA header and the CONTACT header.

After this we can think to a NAT problem.

Regards.

[dwaters]

Hi Daniele,

The "debug ccsip messages" is displayed below:

*Jan 20 11:46:19.556: //-1/xxxxxxxxxxxx/SIP/Msg/ccsipDisplayMsg:

Sent:

REGISTER sip:sip.skype.com:5060 SIP/2.0

Via: SIP/2.0/UDP 10.1.16.22:5060;branch=z9hG4bK285E1C

From: <>990510001XXXXXX@sip.skype.com>;tag=9A74C74-1EC1

To: <>990510001XXXXX@sip.skype.com>

Date: Fri, 20 Jan 2012 11:46:19 GMT

Call-ID: 86CA96C-411A11E1-8002CBD5-9140B2F5

User-Agent: Cisco-SIPGateway/IOS-12.x

Max-Forwards: 70

Timestamp: 1327059979

CSeq: 647 REGISTER

Contact: <990510001XXXXX>

Expires:  3600

Supported: path

Content-Length: 0

Looks like you were stop on! Thank You very much.

Contact: <990510001XXXXX> answers all the questions I think. It’s a NAT problem. I'll setup some new static NAT and see where we go from there.

In my previous experience Static NAT wasn’t required, however in this scenario it looks essential.

[Daniele Giordano]

Is the NAT process performed from your 2801 CUBE or do you use an external router?

You can use "debug ip nat sip" to check the NAT ALG function of cisco router.

The "ip nat service sip udp port 5060" should be enabled to default and should adjust REGISTER fileds that contain private ip addresses.

[Daniele Giordano]

You can also use the "bind" command to use a specific interface for SIP signal:

sip
  bind control source-interface Loopback0
  bind media source-interface Loopback0

Regards.

[dwaters]

It turned out to be a NAT problem.

*Jan 20 13:58:44.664: //-1/xxxxxxxxxxxx/SIP/Msg/ccsipDisplayMsg:

Sent:

REGISTER sip:sip.skype.com:5060 SIP/2.0

Via: SIP/2.0/UDP 10.1.16.22:5060;branch=z9hG4bK2A7170

From: <>99051000XXXXXX@sip.skype.com>;tag=A218DC4-159F

To: <>99051000XXXXX@sip.skype.com>

Date: Fri, 20 Jan 2012 13:58:44 GMT

Call-ID: 86CA96C-411A11E1-8002CBD5-9140B2F5

User-Agent: Cisco-SIPGateway/IOS-12.x

Max-Forwards: 70

Timestamp: 1327067924

CSeq: 681 REGISTER

Contact: <9905100XXXXX>

Expires:  3600

Supported: path

Content-Length: 0

*Jan 20 13:58:44.712: //678/000000000000/SIP/Msg/ccsipDisplayMsg:

Received:

SIP/2.0 200 OK

From: <>99051000XXXXX@sip.skype.com>;tag=A218DC4-159F

To: <>990510001XXXXX@sip.skype.com>;tag=44da78c1-c905628-0-fb5ae6a5-0

Call-ID: 86CA96C-411A11E1-8002CBD5-9140B2F5

CSeq: 681 REGISTER

Via: SIP/2.0/UDP 10.1.16.22:5060;branch=z9hG4bK2A7170

Contact: <990510001XXXX>;expires=300

Expires: 300

Content-Length: 0

Thank You again Daniele!

Daniel.

[dudi_duay]

Having the same problems. How did you solve it? Thanks in advance.