Re: [manet-dlep-rg] Mandatory processing TLVs by routers

[Teco Boot <[e-mail]>]

Op 12 nov. 2013, om 18:58 heeft Stan Ratliff (sratliff) <[e-mail]> het volgende geschreven:

> 
> DLEP peers MUST terminate a session (or note an error and declare a message malformed) if any MANDATORY TLVs are *missing* from a message. 

Yes.


> As to the specific metrics case: 
> 
> Assume that a modem has delivered the 4 MANDATORY TLVs during DLEP peer session initialization. 
> Now assume that a "Destination Update" is presented to the router containing a "new" (unannounced) metric TLV.
> 
> What is the router to do?

This is not about TLVs it doesn't 'understand' but about invalid operation of the peer.

First, the router issues a bug record in vendors tracking system ;-)
Then, it makes the exception. That’s why it is a SHOULD.


Teco
 


> 
> Stan
> 
> On Nov 12, 2013, at 10:32 AM, Teco Boot <[e-mail]>
> wrote:
> 
>> 
>> Op 12 nov. 2013, om 13:51 heeft Taylor, Rick <[e-mail]> het volgende geschreven:
>> 
>>> My understanding of mandatory metrics was:
>>> 
>>> Modems:  MUST advertise support (by giving default values in Initialize message at least) for MDRT,MDRR,CDRT,CDRR, RLQ and Latency (TBD)
>>> 
>>> Routers:  MUST NOT terminate a connection on receipt of any of these TLVs because they do not 'understand' them.
>> 
>> Router SHOULD NOT terminate a connection on receipt of any TLVs it doesn't 'understand'.
>> 
>> Teco
>> 
>> 
>>> Whether the router does anything with any of these metrics is the router's business.
>>> 
>>> Rick Taylor
>>> 
>>>> -----Original Message-----
>>>> From: [e-mail] [mailto:manet-dlep-rg-
>>>> [e-mail]] On Behalf Of Teco Boot
>>>> Sent: 11 November 2013 18:17
>>>> To: Stan Ratliff
>>>> Cc: DLEP Research Group ([e-mail])
>>>> Subject: Re: [manet-dlep-rg] Mandatory processing TLVs by routers
>>>> 
>>>> 
>>>> Op 11 nov. 2013, om 18:44 heeft Stan Ratliff (sratliff)
>>>> <[e-mail]> het volgende geschreven:
>>>> 
>>>>> 
>>>>> On Nov 11, 2013, at 11:00 AM, Teco Boot <[e-mail]> wrote:
>>>>> 
>>>>>> Was Re: [manet-dlep-rg] notes DLEP meeting @ IETF88
>>>>>> 
>>>>>> I'll split of threads, unless one prefer mail storms without clear
>>>> subjects.
>>>>>> 
>>>>>> Op 11 nov. 2013, om 01:55 heeft Stan Ratliff (sratliff)
>>>> <[e-mail]> het volgende geschreven:
>>>>>> 
>>>>>>> Item 1 and 2 seem contradictory to me. Metric values are reported via
>>>> TLVs. If a given metric TLV is MANDATORY, then the router MUST process it
>>>> (at least, the router MUST NOT generate an error because it exists).
>>>>>> 
>>>>>> This is about:
>>>>>> 
>>>>>>>>>>> 1. There are no metric TLVs it is MANDATORY for the Router to
>>>> process.
>>>>>>>>>>> 2. The modem MUST report MDRT, MDRR, CDRT, and CDRR in the Peer
>>>> Discovery message, and make a best effort to accurately report these
>>>> metrics subsequently.
>>>>>> 
>>>>>> Item 2 is the first one to read, then item 1 follows. Routers may
>>>> ignore all TLVs, and for example only use Neighbor Up and Neighbor Down.
>>>>> 
>>>>> 
>>>>> Oh, well.... naturally. When looking at an enumerated list, I *SHOULD
>>>> HAVE* had the general sense to read the second item first.... silly me.
>>>>> 
>>>>> On another topic, to say that I disagree with "... Routers may ignore all
>>>> TLVs..." would be an understatement. That's why TLVs are classified as
>>>> MANDATORY or OPTIONAL. Routers (or modems, for that matter) are free to
>>>> ignore OPTIONAL TLVs. But to mandate that something exist in a message,
>>>> but then say "but you can ignore it"? Doesn't make any sense to me.
>>>> 
>>>> Why do you care? It is perfectly fine you use these mandatory TLV's. Let
>>>> others do their thing.
>>>> 
>>>> Teco
>>>> 
>>>> 
>>>> _______________________________________________
>>>> manet-dlep-rg mailing list
>>>> [e-mail]
>>>> https://www.ietf.org/mailman/listinfo/manet-dlep-rg
>>> The information contained within this e-mail and any files attached to this e-mail is private and in addition may include commercially sensitive information. The contents of this e-mail are for the intended recipient only and therefore if you wish to disclose the information contained within this e-mail or attached files, please contact the sender prior to any such disclosure. If you are not the intended recipient, any disclosure, copying or distribution is prohibited. Please also contact the sender and inform them of the error and delete the e-mail, including any attached files from your system. Cassidian Limited, Registered Office : Quadrant House, Celtic Springs, Coedkernew, Newport, NP10 8FZ Company No: 04191036 http://www.cassidian.com
>> 
>