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Re: [Sip] sip call model
Mahesh Govind wrote:
> Hi,
> can we map sip calls to any particular call model ?
Yes. A complete one-to-one mapping between states will almost
always be impossible, though. This is because you will seldom
have two call models with the same number of states and
transitions (if you did, why map them at all?)
The utility of the resulting mapping will depend on how
granular the states are between the call models. For instance,
a call model with less number of states and low cardinality
transitions can still be mapped to a call model with a high
number of states and many transitions through state splitting.
However, introducing an artificial state in this fashion is
problematic at best. It raises many additional questions: how
does the new state behave in principle with the rest of
the states of the call model in which it was introduced? The
call model may not be amenable to such an artificial
introduction of a new state. How does the designer of the new
state decide on the amount of functionality that should be
in it, in relation to the state it was carved out from? How
easy will it be to realize such a system in working software?
SIP has been mapped to a PSTN call model quite effectively
for certain services (see RFC3976.)
Hope that helps.
- vijay
--
Vijay K. Gurbani, Bell Laboratories, Alcatel-Lucent
2701 Lucent Lane, Rm. 9F-546, Lisle, Illinois 60532 (USA)
Email: vkg at {alcatel-lucent.com,bell-labs.com,acm.org}
WWW: http://www.alcatel-lucent.com/bell-labs
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Date: Tue, 12 Aug 2008 10:43:11 -0500
From: "Vijay K. Gurbani" <vkg at alcatel-lucent.com>
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Subject: Re: [Sip] sip call model
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Mahesh Govind wrote:
> Hi,
> can we map sip calls to any particular call model ?
Yes. A complete one-to-one mapping between states will almost
always be impossible, though. This is because you will seldom
have two call models with the same number of states and
transitions (if you did, why map them at all?)
The utility of the resulting mapping will depend on how
granular the states are between the call models. For instance,
a call model with less number of states and low cardinality
transitions can still be mapped to a call model with a high
number of states and many transitions through state splitting.
However, introducing an artificial state in this fashion is
problematic at best. It raises many additional questions: how
does the new state behave in principle with the rest of
the states of the call model in which it was introduced? The
call model may not be amenable to such an artificial
introduction of a new state. How does the designer of the new
state decide on the amount of functionality that should be
in it, in relation to the state it was carved out from? How
easy will it be to realize such a system in working software?
SIP has been mapped to a PSTN call model quite effectively
for certain services (see RFC3976.)
Hope that helps.
- vijay
--
Vijay K. Gurbani, Bell Laboratories, Alcatel-Lucent
2701 Lucent Lane, Rm. 9F-546, Lisle, Illinois 60532 (USA)
Email: vkg at {alcatel-lucent.com,bell-labs.com,acm.org}
WWW: http://www.alcatel-lucent.com/bell-labs
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mailing list https://www.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use sip-implementors at cs.columbia.edu for questions on current sip
Use sipping at ietf.org for new developments on the application of sip