CHAPTER28 Configuring Supplementary Services
Mediant 1000 Gateway & E-SBC | User's Manual
● The feature is applicable to the following interfaces:
✔ FXO
✔ ISDN
✔ CAS
● The device also identifies emergency calls if the Priority header of the incoming
SIP INVITE message contains the “emergency” value.
● For Trunk Groups configured with call preemption, all must be configured to MLPP
[1] or all configured to Emergency [2]. In other words, you cannot set some trunks
to [1] and some to [2].
● If you are using a Tel Profile, you must configure the 'Call Priority Mode' parameter
in the Tel Profile table and on the Priority & Emergency page with the same value;
otherwise, the Tel Profile parameter is not applied.
● If you configure call preemption using the global parameter and a new Tel Profile is
subsequently added, the TelProfile_CallPriorityMode parameter automatically
acquires the same setting as well.
● For FXO interfaces, the preemption is done only on existing IP-to-Tel calls. In other
words, if all the current FXO channels are busy with calls that were answered by
the FXO device (i.e., Tel-to-IP calls), new incoming emergency IP-to-Tel calls are
rejected.
Multilevel Precedence and Preemption
The device supports Multilevel Precedence and Preemption (MLPP) service. MLPP is a call priority
scheme, which does the following:
■ Assigns a precedence level (priority level) to specific phone calls or messages.
■ Allows higher priority calls (precedence call) and messages to preempt lower priority calls and
messages (i.e., terminates existing lower priority calls) that are recognized within a user-
defined domain (MLPP domain ID). The domain specifies the collection of devices and
resources that are associated with an MLPP subscriber. When an MLPP subscriber that
belongs to a particular domain places a precedence call to another MLPP subscriber that
belongs to the same domain, MLPP service can preempt the existing call that the called MLPP
subscriber is on for a higher-precedence call. MLPP service availability does not apply across
different domains.
MLPP is typically used in the military where, for example, high-ranking personnel can preempt
active calls during network stress scenarios such as a national emergency or degraded network
situations.
MLPP can be enabled for all calls, using the global parameter, CallPriorityMode, or for specific calls
using the Tel Profile parameter, CallPriorityMode.
- 675 -
To Next Page
Loading...
Need help?
General
