Subject: RE: [Ieprep] Preemption

From: "Gunn, Janet NE" <[email-masked]>
Date: Tue, 26 Mar 2002 16:05:18 -0500

It may be a bit more complicated than that.  
 
I am not sure about MLPP, but in eMLPP there are THREE indicators (in
addition to level):
Queueing allowed/Queueing NOT allowed
CAN pre-empt a lower level call/CANNOT pre-empt a call
CAN be pre-empted by a higher level call/CANNOT be preempted by another
call, no matter what the priority.
 
Typically the "Ordinary" call has the lowest priority, but may neither
pre-empt, nor be pre-empted.
 
It seems to me that there MAY be a need for all three indicators in the
context of an IP network also.
 
The indicators MIGHT be tied directly to the level, but (especially if a
single IP network is transporting calls from more than one carrier) might
also be set on a call by call basis. So, it would be desirable for the
protocol to have a way of capturing all 3 indicators.
 
Janet

-----Original Message-----
From: Stuart (Stu) Goldman [mailto:[email-masked]]
Sent: Tuesday, March 26, 2002 9:03 AM
To: Ken Carlberg
Cc: [email-masked]
Subject: Re: [Ieprep] Preemption

Ken, 

Thanks for reminding us of the difference between policy and protocol. 

It seems to me that there are four general cases: 

*	If a given network never preempts, then preemption does not occur
there 

*	If a given network always preempts when needed, then preemption may
occur there 

*	If a given network can do either based on an mandatory indicator,
then it does whatever the indicator directs 

*	If a given network can do either based on an optional indicator,
then the action taken in the absence of the indicator is the DEFAULT action.
To be consistent with the policy statement in this case the default would
seem to be to not preempt. 

Is my understanding correct, or did I miss something? I  used the term
indicator since the information may be part of the protocol or could be
delivered to the network by other means. I didn't want to restrict it to
just being in the protocol.