Subject: Re: [Sipping] Call Waiting - who does the tone (round 2)

From: [email-masked]
Date: Fri, 20 Jun 2003 10:12:46 EDT

In a message dated 6/19/2003 1:28:51 PM Eastern Standard Time, 
[email-masked] writes:

> Dusan,
> 
> Every SIP phone that I am aware of offers call waiting natively. It 
> requires no cooperation on the part of any service provider, and no 
> additional cost by either the end-user nor by any service provider.
> 
> - Nobody has provided any compelling benefit to the end-user to do call 
> waiting in the network
> - Nobody has provided any compelling benefit to the service provider to 
> do call waiting in the network
> - Nobody has demonstrated that any SIP phones implement any of the 
> additional weirdo mechanism that would be required to make network call 
> waiting work as well as locally-implemented call waiting, Nor that 
> there is any compelling economic reason for them to do so.
> 
> thanks,
> -rohan
> 

Rohan,

I've been watching this discussion hoping to see a good answer to the 
beginning question: "Who does the tone?" since this same question about the source of 
tones comes up in many other areas, such as the Assured Service that we 
require. Maybe I missed something, but I don't think I've heard an answer - just 
lots of conjecture and possibilities of how it might be done.

As for the question above - what is the benefit to the service provider to 
doing call waiting in the network?- I'll try to address that one.

It's not a question of "where" it's done, but of who controls it. In the case 
I am interested in, the network provider/service provider/end users (really 
all the same large bunch of people) want a system which offers a number of 
services, including Call Waiting and Assured Service. Part of the requirement is 
to provide certain operational interactions between those services. That is, 
there is an expectation of which service takes precedence when multiple services 
may apply at the same time. If Call Waiting is done completely in the UA, and 
Call Forwarding is done in a proxy, and the decision to preempt a call for 
Assured Service is done someplace else, there is no way that I can imagine that 
the service provider would have any control whatsoever over the precedence of 
these actions or other interactions between them. So the requirement for this 
network is going to be that all services applying to a terminating call must 
be controlled by a single device, I guess it would be a SIP proxy serving the 
called user. The service provider requires standardized ways to do all of the 
required services, controlled by a proxy. Without that, it can not use SIP.

Mike Pierce

---

From: Rohan Mahy <[email-masked]>
Date: Fri, 20 Jun 2003 10:24:45 -0700

On Friday, June 20, 2003, at 07:12 AM, [email-masked] wrote:

> beginning question: "Who does the tone?" since this same question 
> about the source of tones comes up in many other areas, such as the 
> Assured Service that we require. Maybe I missed something, but I don't 
> think I've heard an answer - just lots of conjecture and possibilities 
> of how it might be done.
>
> As for the question above - what is the benefit to the service 
> provider to doing call waiting in the network?- I'll try to address 
> that one.
>
> It's not a question of "where" it's done, but of who controls it. In 
> the case I am interested in, the network provider/service provider/end 
> users (really all the same large bunch of people) want a system which 
> offers a number of services, including Call Waiting and Assured 
> Service. Part of the requirement is to provide certain operational 
> interactions between those services. That is, there is an expectation 
> of which service takes precedence when multiple services may apply at 
> the same time. If Call Waiting is done completely in the UA, and Call 
> Forwarding is done in a proxy, and the decision to preempt a call for 
> Assured Service is done someplace else, there is no way that I can 
> imagine that the service provider would have any control whatsoever 
> over the precedence of these actions or other interactions between 
> them. So the requirement for this network is going to be that all 
> services applying to a terminating call must be controlled by a single 
> device, I guess it would be a SIP proxy serving the called user. The 
> service provider requires standardized ways to do all of the required 
> services, controlled by a proxy. Without that, it can not use SIP.

This is a good question, the answer to which should probably be 
explained more explicitly in the resource-priority draft.  If you want 
to offer a service which duplicates the current MLPP experience, then I 
suggest that you do everything in the UA except for call forwarding 
unavailable, which obviously you cannot do in the UA if it is not 
there.  If you email me the behavior you want, I am happy to sit down 
with you for 30 minutes in Vienna, and show you a cohesive one way to 
implement that behavior on a set of UAs including the appropriate 
security and management. In this case, the real service that the 
service provider is offering is a provisioning and authorization 
service rather than a call process service in the traditional sense.

For an ETS-like service, I believe you have more of a gateway 
prioritization and QoS coordination service.  The only coordination you 
would need with the proxies is to get to the appropriate set of 
gateways (which could even be the same gateways).

Hope this helps.
thanks,
-rohan

> Mike Pierce

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---

From: "James M. Polk" <[email-masked]>
Date: Fri, 20 Jun 2003 12:51:41 -0500

>  That is, there is an expectation of which service takes precedence when 
> multiple services may apply at the same time. If Call Waiting is done 
> completely in the UA, and Call Forwarding is done in a proxy, and the 
> decision to preempt a call for Assured Service is done someplace else, 
> there is no way that I can imagine that the service provider would have 
> any control whatsoever over the precedence of these actions or other 
> interactions between them. So the requirement for this network is going 
> to be that all services applying to a terminating call must be controlled 
> by a single device, I guess it would be a SIP proxy serving the called 
> user. The service provider requires standardized ways to do all of the 

Mike

Are you suggesting that SIP become a (Proxy) Server controlled Protocol (of 
UAs) before you'll use it?

I hope I misunderstood the last bit of your paragraph above

>Mike Pierce

cheers,
James

                                *******************
                    The answer is "42", what's the question?

---

From: "James M. Polk" <[email-masked]>
Date: Fri, 20 Jun 2003 12:56:07 -0500

How did the R-P draft get drug into this thread about Call Waiting and tones?

At 10:24 AM 6/20/2003 -0700, Rohan Mahy wrote:

>>beginning question: "Who does the tone?" since this same question about 
>>the source of tones comes up in many other areas, such as the Assured 
>>Service that we require. Maybe I missed something, but I don't think I've 
>>heard an answer - just lots of conjecture and possibilities of how it 
>>might be done.
>>
>>As for the question above - what is the benefit to the service provider 
>>to doing call waiting in the network?- I'll try to address that one.
>>
>>It's not a question of "where" it's done, but of who controls it. In the 
>>case I am interested in, the network provider/service provider/end users 
>>(really all the same large bunch of people) want a system which offers a 
>>number of services, including Call Waiting and Assured Service. Part of 
>>the requirement is to provide certain operational interactions between 
>>those services. That is, there is an expectation of which service takes 
>>precedence when multiple services may apply at the same time. If Call 
>>Waiting is done completely in the UA, and Call Forwarding is done in a 
>>proxy, and the decision to preempt a call for Assured Service is done 
>>someplace else, there is no way that I can imagine that the service 
>>provider would have any control whatsoever over the precedence of these 
>>actions or other interactions between them. So the requirement for this 
>>network is going to be that all services applying to a terminating call 
>>must be controlled by a single device, I guess it would be a SIP proxy 
>>serving the called user. The service provider requires standardized ways 
>>to do all of the required services, controlled by a proxy. Without that, 
>>it can not use SIP.
>
>This is a good question, the answer to which should probably be explained 
>more explicitly in the resource-priority draft.  If you want to offer a 
>service which duplicates the current MLPP experience, then I suggest that 
>you do everything in the UA except for call forwarding unavailable, which 
>obviously you cannot do in the UA if it is not there.  If you email me the 
>behavior you want, I am happy to sit down with you for 30 minutes in 
>Vienna, and show you a cohesive one way to implement that behavior on a 
>set of UAs including the appropriate security and management. In this 
>case, the real service that the service provider is offering is a 
>provisioning and authorization service rather than a call process service 
>in the traditional sense.
>
>would need with the proxies is to get to the appropriate set of gateways 
>(which could even be the same gateways).
>
>Hope this helps.
>thanks,
>-rohan
>
>>
>>Mike Pierce
>

cheers,
James

                                *******************