TelePresence endpoints DNS question

[danny.yf_li]

Hi , 

I would like to know when the dns server will be queried by TelePresence endpoints. In  other words, when DNS servers are required to be configured on TelePresence endpoints.

I have a couple of Cisco TelePresence endpoints registered on VCSC, do I need to configure DNS servers on endpoints? If yes, should the DNS servers be same as configured on VCSC ?

Thanks

[Patrick Sparkman]

Typically if you're using DHCP, then it will use the DNS address it's getting from the DHCP server.  If you're using a static IP address for the codec, then you must enter DNS address yourself.

I have all of our endpoints and servers use the same DNS servers, or you can use another, it depends on where the endpoints are located and if they can reach the same DNS servers that you're using for your VCS.

[danny.yf_li]

Hi Patrick

      Thanks for your reply.  Sorry for not stating my question precisely.  I would like to know if DNS servers must be configured on TelePresence endpoints or can be left blank.

When will DNS servers be used by endpoints?

If I register TelePresence endpoints on VCSC, all call controls are done by VCSC, so , are DNS servers still required to be configured on endpoints?

Thanks very much!!!

[Patrick Sparkman]

You don't have enter DNS servers on the endpoints if you're using DHCP, although nothing is preventing you from doing so if you want when using DHCP.  However, you do if you're using a static IP address because all the network fields will need to be provided by you, unlike if you were using DHCP.

[danny.yf_li]

Thanks patrick,

     Actually, I am asking about the function about DNS server. Why endpoints need to query DNS servers ?  If the endpoint is standalone, and use h.323 ip dialing only, I think dns server is not used by endpoint. 

     So, if  I register endpoints on VCSC, under what kind of situation , dns server will be queried by endpoints.

Thanks !!

[Jens Didriksen]

If all you want to be able to do is to call other end-points using their public IP address, then DNS is not required - however, if you want to call other external systems using Annex O URI dialling; alias@domain, which you can do if your end-point is running TC4.2 or later, despite being a stand-alone system - then DNS is very much required.

It's a lot of organisations, ours included, which either using private IP addresses, or do not allow incoming IP address dialling.

If you register the end-point to a VCS, then it's still good practice to include DNS details on the end-point even though the VCS can do the DNS lookup, however, it becomes a must if you're running a cluster as then end-points relies on your SRV records for registration etc.

/jens

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[danny.yf_li]

hi Jens,

      If my internal endpoint is registered on VCSC , when I call internal endpoint /external endpoint using Annex O URI dialing, will my internal endpoint query DNS server?  My understanding is that VCS handles all call control signal. Will VCS return resolved destination ip to internal endpoint ?  If yes, then my internal endpoint doesn't query dns server. 

[Jens Didriksen · Accepted solution]

Yes, if you're not using clustered VCS then you'll be fine without configuring DNS server addresses on the end-point.

/jens

[danny.yf_li]

Thanks Jens.