Subject: [Ecrit] Emergency Address Directory section (<draft-schulzrinne-ecrit-requirements-01.txt>)

From: "Tschofenig, Hannes" <[email-masked]>
Date: Tue, 9 Aug 2005 11:25:39 +0200

hi all, 

please find my comments below (#). 

i think that this section should be merged with the previous section
since most requirements directly relate to the mapping protocol.

7.  Emergency Address Directory

   D1.  PSAP Identification:  The mapping information MUST be available
      without having to enroll with a service provider.

# what mapping information? 
# how does this relate to psap identification? 

# this seems to be an operational requirement, if i understood it
correctly. isn't this already covered by R1 partially?  should this, if
needed at all, be moved to section 3? 

      Motivation: The mapping server may well be operated by a service
      provider, but access to the server offering the mapping MUST NOT
      require use of a specific ISP or VSP.

# motivation should not juse capitalized MUST, MAY, SHOULD, etc. 

   D5.  Call setup latency: The directory lookup SHOULD minimize any
      added delay to the call setup.

# i suggest not to talk about call setup latency. we are working on a
mapping protocol. how can we control things that are outside the  scope
of our work? 
# i understand if we have a requirement like:

# Efficiency: The mapping protocol SHOULD have a minimum number of
roundtrips. 

      Motivation:  Since outbound proxies will likely be asked to
      resolve the same geographic coordinates repeatedly, a suitable
      time-limited caching mechanism should be supported.

# the motivation does not match the requirement. if we think that there
is a requirement for caching then we should phrase is at such. 

   D7.  Referral: The querier MUST be able to contact any server and be
      referred to another server that is more qualified to answer the
      query.

      Motivation:  This requirement alleviates the potential for
      misconfigurations to cause calls to fail, particularly for caller-
      based queries.

# this requirement should be related to I3. place them next to each
other. 

   D9.  Baseline query protocol: A mandatory-to-implement protocol MUST
      be specified.

      Motivation:  An over-abundance of similarly-capable choices
      appears undesirable for interoperability.

ciao
hannes

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From: Henning Schulzrinne <[email-masked]>
Date: Tue, 09 Aug 2005 06:29:02 -0400

> # i understand if we have a requirement like:

It talks about *adding* delay to call setup, which is a valid concern. 
The caller doesn't care about the mapping delay, after all, just the 
total. Maybe rephrase as

D5. Minimal additional delay: The directory lookup SHOULD cause minimal 
additional delay at call-setup time.

[Delay at other times, such as during address verification, is not as 
important.]

Henning