Subject: Re: RSVPTE questions

From: "Hong Liao" <[email-masked]>
Date: Mon, 1 Oct 2001 18:59:24 -0400

I think you are perfect right.

But for my understanding, you can choose to log the error  for any error
condition.  But for AppendixB, except the error 23 the list(it was log
locally, and not report to end system), the error msg should be generated
for others and it is mandatory.

For example, if there is unknown style send out in the resv msg, the
resverror msg with error code 06 should be generated by router, it should
be mandatory. right?

Thanks for your email.

Julia

                    David Charlap                                                                                 
                    <David.Charlap@ma        To:     [email-masked]                                                  
                    rconi.com>               cc:     (bcc: Hong Liao/Telcordia)                                   
                                             Subject:     Re: RSVPTE questions                                    
                    10/01/01 06:32 PM                                                                             

Hong Liao wrote:
>
> Yes,  but the way to generate this error whatever they will have
> error msg generated or detected and log locally is the same, right?

An unknown class in a Path or Resv message should generate a PathErr or
ResvErr message.  If it appears in another kind of message (like a
PathTear or ResvConf), then no error should be generated, because there
is no appropriate type of error message to send in the first place.

In all cases, however, whether or not an error was generated, the switch
has the option of logging the error condition.

It's not an either-or situation.  pages 96-97 list a lot of conditions
that routers will typically log.  This is _NOT_ an exhaustive list, nor
is it a mandatory list.  Your can choose to log more events than these,
or you can choose to log fewer, or none at all.  You can log events that
result in the generation of error messages as well as those that don't.

-- David

---

From: David Charlap <[email-masked]>
Date: Thu, 04 Oct 2001 11:55:26 -0400

Hong Liao wrote:
> 
> But for my understanding, you can choose to log the error for any
> error condition.  But for AppendixB, except the error 23 the list
> (it was log locally, and not report to end system), the error msg
> should be generated for others and it is mandatory.
> 
> resverror msg with error code 06 should be generated by router, it
> should be mandatory. right?

The RFC is very clear on this.  But you are going to have to read the
entire section and stop citing indivitual sentences out of context.

Error code 23 is defined as a system error.  It can be generated by any
router for any reason, period.  Any time a fatal error occurs that you
think should be reported, you can generate it.  Other routers are not
expected to know what this means.

The next two paragraphs ("In general...", and "The only....") explicitly
state that errors should not be generated for malformed messages, unless
it is an error condition that some other switch might be able to
correct.  They give an explicit example of a bad C-Type.

Nowhere in here does it say that you should ignore conditions for which
an explicit error code has been defined.  Did you seriously think that
the RFC authors would define an error and then tell you to never
generate it?

The next paragraph ("The choice...") says nothing about not generating
messages.  It says that switches are free to log or not log any error
conditions that they want, and then proceeds to list a bunch of
possibilities.

I really don't understand why you are finding it so difficult to
understand this.  The language is very simple and explicit.

-- David