Subject: Re: [Ieprep] draft-ietf-ieprep-sip-reqs-00.txt

From: [email-masked]
Date: Tue, 27 Aug 2002 08:49:54 EDT

Comments on draft-ietf-ieprep-sip-reqs-00:

2. Instead of CN for the abbreviation, I would suggest SCN (Switched Circuit 
Network).

3. (End of page 4)

Refers to "four resources" although text above just defined five.

4. End of section again refers to four resources (gateway, CN, IP network 
resources, and receiver). The text in Section 3 also defined SIP proxy 
resources.

The meaning of the (x) in the table is not clear. For example, although it 
says that (x) means the resource is in the CN, the first row in the table 
which is the IP-only case has an (x).

REQ-1 implies that the U.S. defense network priority scheme is different than 
Q.735. It is identical. NATO requirements (also five levels) are also the 
same.
The British Government Telephone Preference Scheme (GTPS) is fundamentally 
different. It does not control call setup beyond simply determining who gets 
dial tone.

I suggest this requirement should read:

-----------------------------------------------------------
REQ-1: Not specific to one mechanism or country: The mechanism should not be 
specific to one country or particular priority mechanism. For example, there 
are currently several different priority schemes in widespread use: Q.735 
with five levels, which is the same as the U.S. defense network and NATO; the 
United States GETS (Government Emergency Telecommunications Systems) scheme 
with a single implied higher priority; and the British Government Telephone 
Preference Scheme (GTPS) system, which provides three priority levels for 
receipt of dial tone.
-----------------------------------------------------------

REQ-12 Need to make it clear that the "existing schemes" refers to the PSTN 
and the "future schemes" refers to the plan for IP.

7. The statement that priority mechanisms can be categorized by priority 
queue or preemption is a little restrictive. There are other mechanisms which 
don't fit in either of these two, such as alternate routing and exemption 
from traffic controls. Most of these additional ones could be categorized as 
making additional resources available to the priority calls. I would suggest 
something like:

--------------------------------
Most priority mechanisms can be roughly categorized by whether they:
- use a priority queue for resource attempts
- make additional resources available
- preempt existing resource users (e.g., calls.)
The choice ...
---------------------------------

SEC-9 (Confidentiality) should be separated somewhat from ETS. While it is 
true that many emergency calls would want confidentiality, many regular calls 
also do. Further, the lack of confidentiality would not be a reason for not 
allowing an ETS call to go through, as implied by the statement "must be 
protected".
Since "intercept" is often understood to refer to "lawful intercept", this 
statement about "protected from intercept" should be changed to read 
"unlawful intercept".

SEC-10 Same comment as for SEC-9.

Mike Pierce
Artel