Expressways 12.5 onwards _cisco-uds query

[ravi.pandey]

under this guide :Mobile and Remote Access Through Cisco Expressway Deployment Guide (X12.5) - MRA Infrastructure Requirements [Cisco TelePresence Video Communication Server (VCS)] - Cisco
under :Dual Domain without Split DNS

you can see having _cisco-uds records is no more a requirement, so lets say i have 3 cucm clusters discovred under my Exp-C cluster and am homed under one of those cucm clusters, ILS is enabled. With no _cisco-uds record, which CuCM cluster Exp-C will contact for user's home cluster discovery

[Roger Kallberg]

AFAIK you have to have the _cisco-uds record available in your internal DNS for your clients to reach a UDS server to query for their home cluster and again AFAIK the Exprw-C behaves in the same way, ie it would use this lookup to find a UDS server to ask on behalf of the client what home cluster he/she belongs to.

[ravi.pandey]

from 12.5 you don't  need to have it, it is clearly mentioned , but am curious to know then how it would do home cluster and other service discovery, all the MRA login flows you see on the internet is still from the versions that were old.

By the way, i knew you will be replying

Local DNS (Internal Domains)

Although we recommend that the local, internal DNS is configured with _cisco-uds._tcp.<domain> SRV records, from X12.5 this is no longer a requirement.

[Roger Kallberg]

This is going to be a guess on my end. I’d would think that the C would use the list of configured CM nodes and reach out to one of them in a round robin fashion to ask for the home cluster information.

[Nithin Eluvathingal]

With latest versions For Expressway C to discover CUCM no UDS record is required.

2.12.0.0

[ravi.pandey]

Nithin,

that we already have established, am interested in knowing the answer to my original question

lets say i have 3 cucm clusters discovred under my Exp-C cluster and am homed under one of those cucm clusters, ILS is enabled. With no _cisco-uds record, which CuCM cluster Exp-C will contact for user's home cluster discovery

There is not much in the guides about this change.

Also under this jabber guide it says _cisco-uds record is must, which is in contradiction with what is mentioned in the Expressway MRA guide

Planning Guide for Cisco Jabber 12.8 - Service Discovery [Cisco Jabber for Windows] - Cisco  look for section under "

Collaboration Edge SRV Record"

[Roger Kallberg]

The _cisco-uds record is must if you're not always funneling the clients to connect via MRA. That is stated in the document that you referenced in your original post.

[ravi.pandey]

_cisco-uds  now are only required on what kind of authentication you choose when your jabber is on premise. For MRA if you have expressway 12.5 there is no need, this is the change in 12.5

[Roger Kallberg]

Don't think that I suggested otherwise. Using these install switches are quite rare in my experience, so their somewhat off the norm so to say. If I was unclear somehow please point out where and I'll try my best to give a clearer answer?

[ravi.pandey]

Point is , so far it is all conjectures. I have a case open with Cisco to push them to get the definite answer. I'll come back when I have something definitive to share.
Roger appreciate your participation as always.

[Nithin Eluvathingal]

AFAIK for a single cluster only using MRA, _cisco-uds is not required. But for multi-cluster scenarios _cisco-uds record is must.

2.12.0.0

2.12.0.0