CME with SIP phones - overlay buttons?

[Clifford McGlamry]

Customer is migrating from SCCP to SIP phones on CME.  

Existing phones have overlay buttons configured.  There does not seem to be feature parity for this on the SIP phones.

What's the best way to handle what was a button with 3 dn's overlayed on it on a SIP phone?

[Dan Lukes]

I'm not familiar with SCCP, but I as found the following definition in CUCME System Administrator Guide 

Overlaid directory numbers provide call coverage similar to shared directory numbers because the same number can appear on more than one phone. The advantage of using two directory numbers in an overlay arrangement rather than as a simple shared line is that a call to the number on one phone does not block the use of the same number on the other phone, as would happen if it were a shared directory number.

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It sounds like the overlaid DN is the solution of the issue that doesn't exists on SIP. SIP doesn't block use of the same number on multiple phones. SIP PBX may or may not limit number of simultaneous calls per line - its matter of configuration of PBX, not the phone.

[Clifford McGlamry]

No....not really.



The overlay buttons allow a phone with 2 buttons to provide answer coverage to MORE than 2 DNs. The overlay buttons are configured with multiple DNs, any one of which will trigger ringing on the button if a call arrives on any of the DN's.

[Dan Lukes]

Still no issue with SIP. You can route any call to any button - even many calls to single button. It's just matter of target identification used. If SIP INVITE is send to phone and the target identification match the one configured for a button, then it's considered this button call. Mapping between numbers dialed by caller and target identification is up to PBX.

It seems you are asking wrong question. The core of the phone system is a call control device - not a phone. You are migrating from CME to a SIP based PBX. So correct question is - how to migrate CME's  feature X to my-new-PBX's feature.

It's question we can't answer here. Not only because you didn't disclosed what SIP PBX you are migrating to, but because it's off-topic here.

Note you should learn terminology used by your call control device to understand correctly. It's not the same as the one used in CME world. Not only some terms doesn't exists, but some terms may exists - with different meaning. Beware, terminology used by particular SIP PBX may vary so read documentation of the product you are going to use. Don't focus on feature name. Always check what it mean on particular product.

For example, I suspect your new PBX will know no "overlaid". But it will know groups and shared lines which may, in proper combination, form same results as CME's overlaid.

[rudyhighlan09550]

I think the question asked here was actually about migration from SCCP endpoints to SIP-only endpoints (7800/8800 series?) not about 3rd Party PBX.