Subject: [SIP] Holding Calls UP for Emergency Service

From: "Mo Zonoun" <[email-masked]>
Date: Fri, 2 Mar 2001 14:24:31 -0600

SIP group should consider to define a protocol support for holding a
connection up, and not allowing the call to be dropped by the caller, for
emergency calls. This capability should only be available for emergency
calls (E911) made to the Public Safety Access Point (PSAP). The call should
be maintained until the PSAP initiates the disconnection procedure. Also the
PSAP should be able to upgrade the emergency call path to ensure
availability of resources and the reliability of the call, as well as having
the capability to receive location information automatically without the
caller's consent.  

During an emergency call, the call may be dropped (intentionally or
otherwise) and the PSAP can not call back the caller due to congestion or
other problems. This capability which is already supported by analog
emergency calls on CAMA trunks, ensures that the connection is maintained
until resolved. A similar capability is being developed for ISDN. I believe
the same will be required for IP telephony. My question is what is the way
for SIP to do this.

Mo Zonoun

---

From: "Dean Willis" <[email-masked]>
Date: Fri, 2 Mar 2001 15:18:17 -0600

[SIP] Holding Calls UP for Emergency ServiceNot to laugh, but how do you "hold up" a call when the user yanks the network wire, changes the IP Address, reconfigures the default proxy, or otherwise says "no"?

I suspect we're trying to mandate end-user-device design and behavior in a protocol. Not an Internetty-sort-of-task, I think.

One might envision some sort of signature-enabled mechanism whereby an operator could signal a "do not drop" request to an endpoint, but what the endpoint does with that is, well, up to the endpoint.

The question then becomes the development of a set of requirements for an end device, selecting sub-requirements that can be enabled in a protocol, and specifying only those elements at this level.

--
dean

----- Original Message ----- 
  From: Mo Zonoun 
  To: 'Henning G. Schulzrinne' 
  Cc: [email-masked] 
  Sent: Friday, March 02, 2001 2:24 PM
  Subject: [SIP] Holding Calls UP for Emergency Service

  SIP group should consider to define a protocol support for holding a connection up, and not allowing the call to be dropped by the caller, for emergency calls. This capability should only be available for emergency calls (E911) made to the Public Safety Access Point (PSAP). The call should be maintained until the PSAP initiates the disconnection procedure. Also the PSAP should be able to upgrade the emergency call path to ensure availability of resources and the reliability of the call, as well as having the capability to receive location information automatically without the caller's consent.  

  During an emergency call, the call may be dropped (intentionally or otherwise) and the PSAP can not call back the caller due to congestion or other problems. This capability which is already supported by analog emergency calls on CAMA trunks, ensures that the connection is maintained until resolved. A similar capability is being developed for ISDN. I believe the same will be required for IP telephony. My question is what is the way for SIP to do this.

  Mo Zonoun

---

From: hammer michael <[email-masked]>
Date: Fri, 02 Mar 2001 17:26:11 -0800

Not everything will translate over to the IP world from the PSTN, but some 
will.

A key point will be the ability of the Public Safety Access Point (PSAP) to 
be provided calling name, number, IP address, location information that 
enable them to save lives.  A number of people have died making the 
mistaken assumption that their mobile phone was a lifeline like the 
wireline phone.  If SIP is to be useful in a public service network, some 
meaningful capability will be needed.

Legal cases have ruled that calling an emergency number such as 911 carries 
an implicit approval to the network to provide information that might 
otherwise be withheld due to privacy concerns.

This may be more of an implementation detail than a protocol 
issue.  Proxies could override privacy when translating 911.  PSAP could 
then do automatic callback.  Is it possible for the PSAP to subscribe to 
mobile location events?

Mike

At 03:18 PM 03/02/2001 -0600, Dean Willis wrote:
>Not to laugh, but how do you "hold up" a call when the user yanks the 
>network wire, changes the IP Address, reconfigures the default proxy, or 
>otherwise says "no"?
>
>I suspect we're trying to mandate end-user-device design and behavior in a 
>protocol. Not an Internetty-sort-of-task, I think.
>
>One might envision some sort of signature-enabled mechanism whereby an 
>operator could signal a "do not drop" request to an endpoint, but what the 
>endpoint does with that is, well, up to the endpoint.
>
>The question then becomes the development of a set of requirements for an 
>end device, selecting sub-requirements that can be enabled in a protocol, 
>and specifying only those elements at this level.
>
>--
>dean
>
>From: <mailto:[email-masked]>Mo Zonoun
>To: <mailto:[email-masked]>'Henning G. Schulzrinne'
>Cc: <mailto:[email-masked]>[email-masked]
>calls (E911) made to the Public Safety Access Point (PSAP). The call 
>should be maintained until the PSAP initiates the disconnection procedure. 
>Also the PSAP should be able to upgrade the emergency call path to ensure 
>availability of resources and the reliability of the call, as well as 
>having the capability to receive location information automatically 
>without the caller's consent.
>until resolved. A similar capability is being developed for ISDN. I 
>believe the same will be required for IP telephony. My question is what is 
>the way for SIP to do this.
>Mo Zonoun

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