Emergency Responder and 7920 phones

[sgavan]

Looking for information on how to track location of 7920 wireless phones in a large building for 911 CER dialing.

In lab we have found that 7920's come up as unlocated phones in CER. You can manually define the location within CER and assign a location ERL. Problem is that 7920 are by nature... mobile! So, when a user is at the other end of the building and calls 911, it will use the manually assigned ERL from it's "home" base location.

We can use subnets to divide the building into zones, but this introduces 2 problems. 1) Phones can not roam into the other subnets without droping the calls. 2) It takes up to 5 minutes for CER to "discover" that the phone is on a new subnet... before that, dialing 911 will still use the previous ERL.

Any help or tips are appreciated!

Thanks!

[vmoopeung]

I think CER1.2(1) will not support location tracking of 7920 phones. However, the location tracking for these phones can be implemented using Subnet ERLs. The administrator will need to define subnets for 802.11b phones. When a call is received from an 802.11b phone, it will get routed based on the subnet of the phone. CER1.2(1) supports subnet based ERLs using which you can track 7920 phones at a subnet level location granularity Note: Call routing algorithm in CER gives higher priority to switch-port based ERLs for call routing. If 802.11b phones get discovered behind a switch-port via CAM discovery, the calls from these phones will get routed to the switch-port based ERL

http://www.cisco.com/en/US/products/sw/voicesw/ps842/products_administration_guide_chapter09186a008011c6e8.html#40828

[simon.machielse]

Don't forget the 7920 phones can not raom accros subnets. The phone has to re-register to the ccm again before a new call can be started.

Simon