Subject: [Megaco] H.248.1 - Interpretation of KeepActive flag for Signals descriptor

From: "Pelsemaker, Eric (Eric)" <[email-masked]>
Date: Tue, 5 Nov 2013 13:15:48 +0000

Hi,

In H.248.1 V2,  the following is described with respect to usage of KeepActive flag in Signals Descriptor.

7.1.11      Signals descriptor
....
A new SignalsDescriptor replaces any existing SignalsDescriptor. Any signals applied to the Termination not in the replacement descriptor shall be stopped, and new signals are applied, except as follows. Signals present in the replacement descriptor and containing the KeepActive flag shall be continued if they are currently playing and have not already completed. If a replacement signal descriptor contains a signal that is not currently playing and contains the KeepActive flag, that signal SHALL be ignored. If the replacement descriptor contains a sequential signal list with the same identifier as the existing descriptor, then

*                the signal type and sequence of signals in the sequential signal list in the replacement descriptor shall be ignored; and

*                the playing of the signals in the sequential signal list in the existing descriptor shall not be interrupted.

Suppose a MG receives the following from its MGC

*         At T1: T=53131{ C=70{MF=TEL1102006{SG{amet/em{pc=0,pri=30000}}}}}
At this moment the MG will start sending metering pulse at a rate of one pulse each 30s on termination TEL1102006

*         At T1+183: T=53242{ C=70{MF=TEL1102006{SG{amet/em{KA,pc=0,pri=60000}}}}}
Based on H.248.1, the MG should continue applying the amet/em.
However, as the latter MF command includes another pri-value, I presume the MG has to consider now this NEW pri-value, i.e. at expiry of the current 30s interval the MG has to generate 1 pulse and from then onwards send 1 pulse each 60s. Is my interpretation correct ?
Kr, Eric.