ILS / Global Dial Plan Replication - practical limits?

[KenMeeuwse]

Using ILS / GDPR, is there a practical limit to how many individual DNs can be advertised using the Advertise via ILS checkbox in the Alternate Number section of the DN?

I realize that summarized patterns can be advertised instead, but wondering what the practical capacities are for individual number inclusion when one has a very fragmented dial plan. 

Documentation recommends using summarized patterns in “large” dial plans, but no guidance on what is “large”. 

Supposing one did not adjust any of the default timers for the ILS replication service, is there a rule of thumb for how many records (Alt Numbers) the service can replicate to the other clusters in a default time cycle without overflowing?

[Steven L]

How many numbers/patterns are you wanting to advertise?

I have seen thousands with no issues.

[KenMeeuwse]

20,000 maybe? Yes, I could summarize some with prefixes in a pattern match, but curious about worst case scenario. Supposing "all" of them were advertised on the DN page (EAN) Advertise Globally via ILS. 
Wondering how log it would take to sync a series like that. Default value on the ILS Configuration > Intercluster Lookup Service Configuration > Synchronize Clusters Every is 10 minutes with a range up to 1440 minutes.
Has anyone needed to increase that value to accommodate large sets of individual DN advertisements? 

[Roger Kallberg]

20K should not be a problem. That’s not really a large number of directory numbers for a CM deployment. Large would be in the range of >100K I would say. That said my personal recommendation would be to use advertised patterns whenever possible as that much easier to maintain.