RE: Fwd: draft-ietf-iptel-trip-gw-00.txt has been posted

Dhaval Shah <[email protected]> Mon, 10 Jun 2002 18:15:24 -0700
Newsgroups gmane.ietf.iptel
Message-ID <[email protected]>
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Hi Anna,

Please see comments inlined below..

At 02:34 PM 6/10/2002 -0400, Anna Cheung wrote:
>Hi Dhaval,
>
>I have some questions after reading the trip-gw draft, and hope
>you or somebody in the work group could clarify.
>
>Thanks
>/Anna
>
>
>1) Available Capacity (AC) is defined as non-transitive
>in the draft. I'm just wondering if it should be transitive instead.
>The reason being if the LS fronting the GW does not advertises
>the AC of the route to other LS's in the core of the network, then there
>could be cases where a route is selected with higher TotalCapacity but
>lower available Capacity. (From the draft, it seems to be
>the reason it is defined as non-transitive is due to the fact that
>it might change frequently. But if the GW only advertises when
>somethrehold is crossed, then the frequency might not be a big problem
>for the LS ??)

This would add another level of complexity and gets into tuning
to avoid staleness etc. We analyzed this and thought of not including at 
this time.

>
>2) Section 4.4 prefix attribute, is it saying that the prefix attribute is
>a conditional mandatory attribute for the trunk address family and CIC
>address family?  I'm a bit confused by the statement "conditional mandatory
>(if reachable routes is present)"

This means that if the reachableroutes attribute is present, then the prefix
attribute must be present. A length of zero for the prefix attribute 
indicates a prefix
that matches all prefixes for the respective address family type and 
application protocol.
I thought I had included that statement in the draft but loox like it got 
removed while re-arranging
the Prefix attributes section. Will add it in the next rev.

>3) When a GW advertises a route of type trunk address family (or CIC address
>family), if attribute prefix attribute is NOT present, does it mean the 
>advertised
>trunk (or CIC) can be used to reach ANY prefix?

No. Please see note above.

>
>4) Can you please clarify why carrier attribute must not be used with 
>trunk family
>and trunk attribute must not be used with the CIC family ?

Introduces hierarchy and complexity amongst other reasons and was not 
deemed important
enough at this stage. We have noted it as a future issue.

>5) Reading section 4.10.1, I'm under the impression that an LS may receive
>alternative routes from the same gateway for a given destination. Is this 
>true?
>  Doesn't the subsequent advertisment of a given route from the same GW 
> just replaces
>the previous advertisement?

Section 4.10.1 tries to address the case where the LS may receive 
alternative routes
for the same destination from *different* gateways. If the same gateway 
wants to advertise
alternative routes for a given destination, then it can send them in one 
update to the LS.

>6) When a GW advertise an update with the follows:
>- trunk address family,
>- trk value=trk1,
>- prefix attribute=1613,
>- nexthop = NH1
>
>The update is saying that route trk1 and prefix 1613 is
>reachable via NH1.  Could we also interpret that 1613
>is reachable via NH1?

Yes, if you don't care about trk1.

Hope this helps.

Thx,
Dhaval

>
>-----Original Message-----
>From: Dhaval Shah [mailto:[email protected]]
>Sent: Sunday, June 09, 2002 2:20 PM
>To: [email protected]
>Subject: [IPTEL] Fwd: draft-ietf-iptel-trip-gw-00.txt has been posted
>
>Hi Folx,
>
>Just a follow-up to the draft posting.
>
>The main changes in this version are:
>- Removed Carrier-Trunkgroup attribute and address family and
>    references to it.
>- Added Terminology and Definitions section.
>- Updated CallSuccess attribute.
>- Added Prefix attribute.
>- Added Carrier attribute.
>- Added TrunkGroups attribute.
>- Added TrunkGroup Address Family.
>- Added Carrier Address Family.
>- Added Route Consolidation section.
>- Added some more references.
>
>A couple of open issues that come to mind are:
>- International carrier ids
>- Jonathan had a suggestion regarding having an update rate capability 
>that the LS would send
>to the gateway. The purpose would be to have the gateway not send updates 
>at a rate higher than the
>specified number.
>
>Thx,
>Dhaval
>
>
>
>
>
>
>
>>Date: Fri, 07 Jun 2002 07:51:22 -0700
>>To: [email protected]
>>From: Dhaval Shah <[email protected]>
>>Subject: draft-ietf-iptel-trip-gw-00.txt has been posted
>>Cc: [email protected], [email protected], [email protected], 
>>Rajneesh Kumar <[email protected]>
>>Bcc: [email protected], [email protected], [email protected], 
>>[email protected], [email protected], [email protected], [email protected], 
>>[email protected], [email protected], [email protected]
>>
>>Hi Folx,
>>
>>The draft is now available on the ftp server:
>>ftp://ftp-eng.cisco.com/dhaval/draft-ietf-iptel-trip-gw-00.txt
>>
>>If someone has problems retrieving it, please email directly and we will
>>email a copy to you.
>>
>>Please let us know if you have any questions.
>>
>>Thx,
>>Dhaval (for the trip-gw team)

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<html>
<font size=3>Hi Anna,<br>
<br>
Please see comments inlined below..<br>
<br>
At 02:34 PM 6/10/2002 -0400, Anna Cheung wrote:<br>
</font><blockquote type=cite cite><font face="arial" size=2 color="#0000FF">Hi
Dhaval, </font><font size=3><br>
&nbsp;<br>
</font><font face="arial" size=2 color="#0000FF">I have some questions
after reading the trip-gw draft, and hope </font><font size=3><br>
</font><font face="arial" size=2 color="#0000FF">you or somebody in the
work group could clarify.&nbsp; </font><font size=3><br>
&nbsp;<br>
</font><font face="arial" size=2 color="#0000FF">Thanks</font><font size=3><br>
</font><font face="arial" size=2 color="#0000FF">/Anna
</font><font size=3><br>
&nbsp;<br>
&nbsp;<br>
</font><font face="arial" size=2 color="#0000FF">1) Available Capacity
(AC) is defined as non-transitive<br>
in the draft. I'm just wondering if it should be transitive 
instead.<br>
The reason being if the LS fronting the GW does not advertises<br>
the AC of the route to other LS's in the core of the network, then there
<br>
could be cases where a route is selected with higher TotalCapacity
but<br>
lower available Capacity. (From the draft, it seems to be<br>
the reason it is defined as non-transitive is due to the fact that<br>
it might change frequently. But if the GW only advertises when<br>
somethrehold is crossed, then the frequency might not be a big
problem<br>
for the LS ??)</font></blockquote><br>
This would add another level of complexity and gets into tuning<br>
to avoid staleness etc. We analyzed this and thought of not including at
this time.<br>
<br>
<blockquote type=cite cite><font size=3>&nbsp;<br>
</font><font face="arial" size=2 color="#0000FF">2) Section 4.4 prefix
attribute, is it saying that the prefix attribute is<br>
a conditional mandatory attribute for the trunk address family and
CIC<br>
address family?&nbsp; I'm a bit confused by the statement
&quot;conditional mandatory <br>
(if reachable routes is present)&quot; </font><font size=3><br>
</font></blockquote><br>
This means that if the reachableroutes attribute is present, then the
prefix<br>
attribute must be present. A <font size=3>length of zero for the prefix
attribute indicates a prefix <br>
that matches all prefixes for the respective address family type and
application protocol.<br>
I thought I had included that statement in the draft but loox like it got
removed while re-arranging<br>
the Prefix attributes section. Will add it in the next rev.<br>
<br>
</font><blockquote type=cite cite><font face="arial" size=2 color="#0000FF">3)
When a GW advertises a route of type trunk address family (or CIC address
<br>
family), if attribute prefix attribute is NOT present, does it mean the
advertised<br>
trunk (or CIC) can be used to reach ANY prefix? 
</font></blockquote><br>
No. Please see note above.<br>
<br>
<blockquote type=cite cite><font size=3>&nbsp;<br>
</font><font face="arial" size=2 color="#0000FF">4) Can you please
clarify why carrier attribute must not be used with trunk family <br>
and trunk attribute must not be used with the CIC family
?</font></blockquote><br>
Introduces hierarchy and complexity amongst other reasons and was not
deemed important <br>
enough at this stage. We have noted it as a future issue.<br>
<font size=3>&nbsp;<br>
</font><blockquote type=cite cite><font face="arial" size=2 color="#0000FF">5)
Reading section 4.10.1, I'm under the impression that an LS may receive
<br>
alternative routes from the same gateway for a given destination. Is this
true? </font><font size=3><br>
</font><font face="arial" size=2 color="#0000FF">&nbsp;Doesn't the
subsequent advertisment of a given route from the same GW just replaces
<br>
the previous advertisement?</font></blockquote><br>
Section 4.10.1 tries to address the case where the LS may receive
alternative routes<br>
for the same destination from *different* gateways. If the same gateway
wants to advertise<br>
alternative routes for a given destination, then it can send them in one
update to the LS.<br>
<br>
<blockquote type=cite cite><font face="arial" size=2 color="#0000FF">6)
When a GW advertise an update with the follows: <br>
- trunk address family, <br>
- trk value=trk1, <br>
- prefix attribute=1613, <br>
- nexthop = NH1</font><font size=3><br>
&nbsp;<br>
</font><font face="arial" size=2 color="#0000FF">The update is saying
that route trk1 and prefix 1613 is<br>
reachable via NH1.&nbsp; Could we also interpret that 1613 <br>
is reachable via NH1? </font></blockquote><br>
Yes, if you don't care about trk1.<br>
<br>
<font size=3>Hope this helps.<br>
<br>
Thx,<br>
Dhaval<br>
<br>
<blockquote type=cite cite>&nbsp;</font>
<dl><font face="tahoma" size=2>
<dd>-----Original Message-----
<dd>From:</b> Dhaval Shah
[<a href="mailto:[email protected]" eudora="autourl">mailto:[email protected]</a>]
<dd>Sent:</b> Sunday, June 09, 2002 2:20 PM
<dd>To:</b> [email protected]
<dd>Subject:</b> [IPTEL] Fwd: draft-ietf-iptel-trip-gw-00.txt has been
posted<br>
<br>
</font><font size=3>
<dd>Hi Folx,<br>
<br>

<dd>Just a follow-up to the draft posting.<br>
<br>

<dd>The main changes in this version are:
<dd>- Removed Carrier-Trunkgroup attribute and address family and
<dd>&nbsp;&nbsp; references to it.
<dd>- Added Terminology and Definitions section.
<dd>- Updated CallSuccess attribute.
<dd>- Added Prefix attribute.
<dd>- Added Carrier attribute.
<dd>- Added TrunkGroups attribute.
<dd>- Added TrunkGroup Address Family.
<dd>- Added Carrier Address Family.
<dd>- Added Route Consolidation section.
<dd>- Added some more references.<br>
<br>

<dd>A couple of open issues that come to mind are:
<dd>- International carrier ids
<dd>- Jonathan had a suggestion regarding having an update rate
capability that the LS would send 
<dd>to the gateway. The purpose would be to have the gateway not send
updates at a rate higher than the
<dd>specified number.<br>
<br>

<dd>Thx,
<dd>Dhaval<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<blockquote type=cite cite>
<dd>Date: Fri, 07 Jun 2002 07:51:22 -0700
<dd>To: [email protected]
<dd>From: Dhaval Shah &lt;[email protected]&gt;
<dd>Subject: draft-ietf-iptel-trip-gw-00.txt has been posted
<dd>Cc: [email protected], [email protected], [email protected],
Rajneesh Kumar &lt;[email protected]&gt;
<dd>Bcc: [email protected], [email protected], [email protected],
[email protected], [email protected], [email protected], [email protected],
[email protected], [email protected], [email protected]<br>
<br>

<dd>Hi Folx,<br>
<br>

<dd>The draft is now available on the ftp server:
<dd><a href="ftp://ftp-eng.cisco.com/dhaval/draft-ietf-iptel-trip-gw-00.txt" eudora="autourl">ftp://ftp-eng.cisco.com/dhaval/draft-ietf-iptel-trip-gw-00.txt</a><br>
<br>

<dd>If someone has problems retrieving it, please email directly and we
will
<dd>email a copy to you.<br>
<br>

<dd>Please let us know if you have any questions.<br>
<br>

<dd>Thx,
<dd>Dhaval (for the trip-gw team) </blockquote></font>
</dl></blockquote></html>

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