[Iptel] comments on draft-ietf-iptel-tgrep-01.txt

["Bob Penfield" <bpenfield@acmepacket.com>]

I apologize for lateness of these comments and for any duplicates.

In general, The relationships and differences between TRIP and TGREP are too
vague. This spec does contain protocol procedures and requirements for TRIP
as well as for TGREP since it introduces new attributes and address families
that can be used in TRIP. I recommend presenting the overall architecture in
the introduction and clearly defining the elements of the model (LS, TGREP
Speaker/Gateway, TGREP Receiver, etc.) and use those terms consistently
throughout the spec so that it is clear which requirements apply to which
elements. For example, when it talks about originating and disseminating
attributes, it should be clear who is allowed to do what.

Section 3.2: The "MUST NOT" is a duplicate of the requirement in section
3.2.5. Remove "unless the LS is sure...", MUST NOT means NEVER. If you want
to emphasize the fact that the attribute is not propagated, I suggest text
along the lines of "When the AvailableCircuits attribute is received in a
route, it is not propagated (see section 3.2.5)".

Section 3.3: The "MUST NOT be propagated" duplicates the requirement in
section 3.3.5 (see 3.2 comment above).

Section 3.3.1: suggest adding "within some window of time" (or words to that
affect to "...represents total number of attempted calls...".

Section 3.3.5: remove "in most cases" since the MUST NOT makes it unsuitable
in all cases.

Section 3.4.5: change ".. this attribute should disseminate.." to ".. this
attribute SHOULD disseminate ...".

Section 3.6: change "... that the gateway can complete calls to" to "...
that the gateway uses to complete calls". The carrier is a transport, not a
destination.

Section 3.6.1: The carrier length should be variable. The carrier is usually
derived from dialed digits, thus deployments will likely use the carrier
codes used in dialing as TGREP carriers to avoid the additional overhead of
mapping dialed carrier codes to TGREP carrier codes. The US uses 5-digit
carrier codes in dialing (e.g. 10288 for AT&T as in 1010288). Is it to be
assumed that for country code of less than three digits that the 3-octet
country-code is padded with NULL bytes?

Section 3.7.1: page 15: The syntax of the Carrier Address Family should
match the syntax of the Carrier Attribute.

Section 3.9: change "A gateway uses TRIP" to "A gateway uses TGREP".

Section 4: The fact that TRIP and TGREP should share the IANA registry for
capabilities, attributes, address families, and protocols needs to be
clearly specified.

cheers,
(-:bob

Robert F. Penfield
Chief Software Architect
Acme Packet, Inc.
130 New Boston Street
Woburn, MA 01801
bpenfield@acmepacket.com


_______________________________________________
Iptel mailing list
Iptel@ietf.org
https://www.ietf.org/mailman/listinfo/iptel