Question on Cluster name and DNS SRV records of VCS Cluster

[Arbenjamin]

We have some inquries on the Appendix 9 – Cluster name and DNS SRV records of the document- Cisco_VCS_Cluster_Creation_and_Maintenance_Deployment_Guide_X7-1.

In our current network, we have installed TMS on the Window server 2003 R2, however, we faced some problems in seting up the DNS SRV records.

1.Is the window server 2003 R2 support the related DNS SRV record?

2.Anyone has tried to configure the SRV record or NAPTR  by the window server 2003 R2? It is beacuse we are confusing in setting up such record.

Best regards,

Ben

[Tomonori Taniguchi · Accepted solution]

You should able to configure SRV record on Windows 2003 R2 Server using “Other New Records…”.

From “Other New Records…”, select “Service Location (SRV) and configure SRV record that you like to add.

For example SIP/TCP record.

[1st record]

Service: _sip

Protocol: _tcp

Priority: 0

Weight: 0

Port number: 5060

Host offering this service: vcs1.domain.com

[2nd record]

Service: _sip

Protocol: _tcp

Priority: 0

Weight: 10

Port number: 5060

Host offering this service: vcs2.domain.com

Please note that you need to create two service record separately.

Windows SRV record doesn't support "." after service and protocol, you can just configure service and protocol without "." which add automatically in background.

[Arbenjamin]

Hi Tomonori Taniguchi,

Thank for your clear explaination, we have created the related cluster under your instraction.

However, we still have some questions in the your printed screen,

1.The cluster name in your example is lab003.com?

2.Is there any DNS configuration is required ? As my endpoints is not able to register to the cluster.

3. I am confusing in the 63 of the Cluster creation and maintenance, is it nesscary to configure " Endpoints supporting SIP DNS SRV"?

Many thanks.

Best Regards,

Ben

[Tomonori Taniguchi · Accepted solution]

> 1.The cluster name in your example is lab003.com?

Yes, cluster name use “lab003.com” for this case.

> 2.Is there any DNS configuration is required ? As my endpoints is not able to register to the cluster.

Yes, for H323 Endpoint registration using DNS SRV record, you will need to configure "_h323rs._udp" SRV service and each VCS A-record configuration on DNS.

For SIP, you will need "_sip._tcp", "_sip._udp" or "_sips._tcp" SRV service and each VCS A-record configuration on DNS.

> 3. I am confusing in the 63 of the Cluster creation and maintenance, is it nesscary to configure

>"Endpoints supporting SIP DNS SRV"?

I'm not sure if I correctly understand your question, but not all Endpoint does support SIP proxy configuration with SRV-DNS base addressing.

This is very depend on Endpoint model as well software version.

[Arbenjamin]

Hi Tomonori Taniguchi,

Thanks a lot.

With your great support, we have biult the DNS records. However, the tandberg C20 can't resolve the Cluster name (even the domain name of the VCS).In our PC, it can resolve the cluster name and the domain name as well.

Would you mind providing some comment for us.

Thank you a lot.

Best Regards,

Ben

[Tomonori Taniguchi]

Great to hear you have managed to configured it.

> However, the tandberg C20 can't resolve the Cluster name (even the domain name of the VCS).

Does your Endpoint pointing to same DNS server as your PC?

Have you reboot your C20 after you made DNS configuration, and still facing same issue?

Also have you try this with TC5 software?

[Arbenjamin]

Hi Tomonori Taniguchi,

Thank you for your support

The Endpoint and PC are using the same DNS server 192.168.20.133

We have tried to telnet to the endpoint, and ping the DNS name of the single VCS unit(

vcsControl1.vcs.vega-global.com), however, it can't return with IP address.

The unit is using TC5.1 , and we have tried to factory reset the unit.However, the problem still exist.

On the ways, we have other silly questions. If we want to add the extra SRV service like  "_sip._tcp", "_sip._udp" or "_sips._tcp", how can know the exactly firewall port number?

Anyways, Thank for your kindly support until now ! Thx

Best Regards,

Ben

[Tomonori Taniguchi]

> We have tried to telnet to the endpoint, and ping the DNS name of the single VCS unit

> (vcsControl1.vcs.vega-global.com), however, it can't return with IP address.

I assume you login C-series Endpoint as root and ping one A-record (vcsControl1.vcs.vega-global.com) which mapped to SRV record.

If these pings are failing, you probably need to review your DNS configuration.

Maybe you can sniffer traffic on your E-series Endpoint and verify communication between DNS server (query and response).

You can use "tcpdump" command to sniffer the ip packet on C-series Endpoint.

  Step 1: Login as root on Endpoint and execute "tcpdump -w /tmp/dns.pcap -s 1500 ip and not port 22" command

  Step 2: Make an action that will require DNS lookup (i.e. ping to VCS host name from other SSH windows).

  Step 3: Stop sniffering the packet (Ctrl + C)

  Step 4: Download pcap file from C-series Endpoint saved under /tmp directory (i.e using WinSCP application).

> how can know the exactly firewall port number?

Port number for each SIP SRV service is as follow;

  _sip._tcp - 5060

  _sip._udp - 5060

  _sips._tcp - 5061

Please refer to page 6 of SRV record presentation available from https://supportforums.cisco.com/docs/DOC-25395.

Please note this is signaling port, call will require additional ports for media channels (and H.245 signaling ports for H.323 call)

[Tomonori Taniguchi · Accepted solution]

[Tomonori Taniguchi]

BTW, additional SRV information (service, protocol, port, etc.) is available at https://supportforums.cisco.com/docs/DOC-25395.

[Arbenjamin]

Dear Tomonori,

Thank you for your kindly support, we can setup the cluster in our testing enviorment.

Best Regards,

Ben

[Tomonori Taniguchi]

Great, thanks for your update and sharing the result (good reference for other with same approch).