UDS service and ILS

[aalejo]

Does somebody know WHY is mentioned everywhere (CCO, networkers,etc) that UDS home cluster discovery requires ILS, WHEN UDS home cluster discovery DOES NOT requires ILS to be even operational.

Thank

Alex

[Jaime Valencia]

Exactly on what scenario are you making this assumption?

[aalejo]

Multi cluster scenario. I have ILS disable in all clusters and jabber is able to discover home cluster internal and also using MRA.

Traces shows that UDS works perfectly without ILS being enable.

On each cluster, each remote cluster was added manually.

version 10.5

[Ayodeji Okanlawon]

####### Here is my Part A--Argument (please read Part B )########

ILS is required for UDS to discover home cluster in a multi cluster environment.

Within a single cluster it is not required..

Example.

Cluster 1--userA
Cluster 2--userB

DNS record has two UDS servers..cluster 1 and cluster 2 UDS..
When userB's Jabber attempts to do service discovery, DNS returns cluster1-UDS server ( it could also return cluster 2-UDS and no ILS will be needed)

When cluster1-UDS attempts to discover userB-home cluster, it first looks in its local cluster, finds userB but the home cluster button is not ticked, hence it needs to find a way to know where the home cluster is. This is where ILS comes in..

This argument is also corroborated with the details in this document..

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/jabber/11_5/CJAB_BK_C6FFF6D8_00_cisco-jabber-115-planning-
guide/CJAB_BK_C6FFF6D8_00_cisco-jabber-115-planning-guide_chapter_0101.html#CJAB_RF_C74F634A_00

#### PART B- ILS is not required ####

Contrary to what I have believed just like others as explained above, a defect has actually been opened to address the fact that it is not needed.

https://quickview.cloudapps.cisco.com/quickview/bug/CSCuq45460

Now to support the fact that we done need ILS, here is a key question..

Will UDS work if ILS is non-functional?

A: Yes. It will continue to work as long as the advanced configuration page has the configuration of the Nodes with UDS activate

As long as both clusters can see the servers offering UDS services ILS is not needed for this.

Thank you for asking, you have helped me a great deal.

[aalejo]

Agree, funny part is networkers (2016+) and everywhere still mentioning that ILS is needed when they are indeed two unrelated features that use two independent services on CUCM.

Thanks for the detailed  information, i could not find that bug id.

Alex

[carlnewton]

Bump for this... Cisco have multiple times advised me that ILS is required for UDS lookup.

I can confirm that in my experience, it is NOT.

ILS is required for GDPR (Global dial plan replication) But the only thing required for Jabber logins is UDS, despite what the docs say.

[jonathan.salter]

---

Will UDS work if ILS is non-functional?

A: Yes. It will continue to work as long as the advanced configuration page has the configuration of the Nodes with UDS activate

Where is this setting? Getting ready to deploy Jabber globally.

---

[carlnewton]

Advanced Features.-> Cluster View

Add a new cluster. Activate UDS.

[r.rigo]

They right answer regarding rerouting service on the right Cluster for a client user request.

[stobar1101]

Change something for the new versions of CUCM, I don't see the UDS option.