Polycom MGC Administrator, Administrator'S Manual

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MGC Administrator’s Guide
7-13
H.323 to H.320 or H.323 Calls
When an H.323 endpoint calls an endpoint (H.323 or H.320), two different
methods may be used to reach the same endpoint: Forwarding Service (H.323
to H.320) or Address Book.
With the Address Book method, the Gateway includes a conversion table in
which each E.164 ID number is assigned either the phone number of an H.320
destination endpoint or an IP address or Alias of an H.323 endpoint. The
Gateway also includes a table of Session Profiles. Each Session Profile
describes the call parameters such as the network service to be used to dial to
the destination endpoint, the line rate and the transcoding mode. Each entry in
the table is identified by an E.164 format ID. When the call originator dials
the E.164 ID, the gateway converts this ID to the destination endpoint dial
number or IP address/Alias. The call parameters such as Line Rate, Restricted
(ISDN only) and Transcoding Method are indicated by a Session Profile ID.
Address Book IP-to-ISDN
This method is used when an “Internal” IP endpoint calls an external ISDN
number. It enables speed dialing as the IP endpoint only enters the endpoint
ID in the table and does not have to enter the whole number (many digits).
With the Address Book method, the Gateway includes a conversion table in
which each E.164 ID number is assigned a destination H.320 (ISDN/PSTN)
number. In this method, the destination endpoint details are taken from the
Address Book table, enabling speed dialing from H.323 endpoints to ISDN
endpoints.
In the following examples, the number 83 represents the H.323 Network Service
prefix defined for the MCU and that is registered with the Gatekeeper. It is used
by the Gatekeeper to identify the MCU and network cards that should be used to
handle the call.