CME Over-Relay

The max number of DNs assigned to IP phone is limited by number of phone buttons. However, using overrelay-dn option this can be extended. Each phone button can have 25 DNs which mean that 7960 phone can have upto 150 DNs.

Important points:

• Multiple phones can share the same overrelay set (combination of overrelay + shared lines)

• One DN can participate in multiple overrelay sets (combination of overrelay + shared lines)

• DNs in one overrelay set can have same extensions or different extensions. In case of same extension, dial-peer hunting configuration is used to select the DN which will ring first within overrelay set (combination of overrelay + multiple DNs with same extension).
• DNs in overrelay set can use single-line or dual-line. Octo-line isn't supported.
• The same concept of huntstop, huntstop channel, and preference  is applicable when overrelay is combined with shared-lines or multiple DNs sharing same extension.
• Assume that two phones are sharing same overrelay set, assigned to button 1, and each DN in the set is a single line. In case DN 1 is in-use in phone A and phone B user press button 1, DN 2 will be engaged and not DN 1.
• Assume that 3 DNs are overlaid in one set. In case the phone is engaged with DN 1, calls to DN 2/3 in the set won't generate any notification. For this purpose, call-waiting can be combined with overrelay feature to overcome this issue.
• Again, assume that 3 DNs are overlaid in one set. In case the phone is engaged with DN 1, calls to DN 2/3 in the set won't generate any notification. Optionally, you can dedicate other buttons in the same phone to ring when new calls are targeting DNs 2/3
• CME services such as Call Park and Call Pickup are supported with Overlaid DNs
• When overrelay-dn is engaged, the phone user won’t be able to know the called-dn which is part of overlaid set. This can be solved using service dnis overlay feature. This will display the name of the DN called which is part of overlaid set on phone screen. Also, this feature will display the DN of overlaid set which is placed on-hold.

E.g.

telephony-service

service dnis overlay

!

ephone-dn  3

 number 6001

 name OVRLY-1

 preference 5

!

ephone-dn  4

 number 6002

 name OVRLY-2

 preference 5

!

ephone-dn  5

 number 6003

 name OVRLY-3

 preference 5

!

ephone  1

 button  1:1 2:6 3o3,4,5

 

Configuration Template

ephone-dn dn-tag [dual-line]

 number number

 preference preference-order

 huntstop

 huntstop channel

 call-forward noan

 call-forward busy

!

ephone phone-tag

 mac-address mac-address

 button button-number {o | c} dn-tag,dn-tag[,dn-tag...] button-number {x} overlay-button-number          !!!... O:  overlaid, C: overlaid + call-waiting, X: overlaid + dedicated button

Note: 'X' overlaid should be combined with 'O' overlaid. It can't be used alone or combined with 'C'.