GK and Tech prefix

NAVIN PARWAL · ‎12-20-2006

Folks,

I am confussed. Reading about GK. The routing algorith says that if the zone matches check to see if the zone is local, if the zone if local check to see if technology prefix wa defined. My question is why is the technology prefix checked again after the zone is matched to local zone.

Also when the tech prefix is passed to the gatekeeper does it strip the tech prefix before passing it on to the gateway or not?

thisisshanky · ‎12-20-2006

Few things about tech-prefix:

I. Tech-prefix could be defined to route a call locally to a device registered in a local zone or to hop-off calls to a remote zone (via a remote gatekeeper).

II. So the GK routing algorithm has to check at first if a tech-prefix was matched in the incoming DNIS and if one was found,

a. if it matches with a hop-off tech-prefix defined in the system. If it does then hop-off the call to the remote gatekeeper defined.

b. If not, then normal routing continues.

III. Once a zone has been matched, the zone could be local or remote.

a. If the zone is remote, then no need to continue checking tech-prefixes.

b. If the zone is local, and there are multiple devices registered in that zone, the gatekeeper needs to figure out which device should receive the call. This is selected based on a tech-prefix check for a second time.

IV. The gatekeeper doesnt strip the tech-prefix, so you have to do the necessary at the receiving gateway to strip the tech-prefix. (usually num-exp should help)

HTH

Sankar

PS: please remember to rate posts!

Sankar Nair
UC Solutions Architect
Pacific Northwest | CDW
CCIE Collaboration #17135 Emeritus

NAVIN PARWAL · ‎12-20-2006

Many thanks for the response, you are awesome!

Do you have a sample config that explains how the tech prefix match works after the gatekeeper has detected that the zone is local.

gogasca · ‎12-20-2006

http://www.cisco.com/en/US/tech/tk1077/technologies_tech_note09186a00800a8928.shtml#tp

The technology prefix is checked again because multiple prefixes can exist for a single local zone, and a gateway belonging to multiple zone prefixes might register to the GK.

The technology prefix is stripped from the called number when the gateway attempts to match a zone prefix. However, the full number with the technlogy prefix is delivered to the destination gateway.