Re: Counting Send DE Frames for Frame Relay MIB

[James Watt <[e-mail]>]

[e-mail] writes:
+---------
|> Caralyn wrote:
|> As for the following suggestion, how would a network manager make use of this?
|> Personally, I would like not to add this, but if there is good reason to add
|> it and others like it, what the heck.
|
|I think the object is useful, from the basic perspective that if you are/can
|set the bit, its nice to know how many.  Also, if you are setting the bit
|you can determine the percentage of traffic your sending with the DE bit set
|(ie, how often you're exceeding CIR).
+---------
This is exactly what I'm worried about.  If a DTE sets the DE bit, it has
nothing to do with CIR - it just chose to set it.  Don't forget the switch
has a leaky bucket and I somehow doubt that the DTE is running the same
filter aligned perfectly in time with the switch.

This is why I wanted the warning.

In any event, if you are sending frames with DE set, you could well want to
count them.  The point in the previous mail about comparing this to the
Rx counter in RFC 1604 is a good point...

+-----------
|> James wrote:
|> I would suggest that if we absolutely must add this object, we add
|> text that reminds the implementor/user that the network will classify
|> the traffic as normal or excess based on CIR/Bc/Be and _not_ the DE bit
|> although it may still use the DE bit to determine discard preference.
|
|I don't agree with this.  At least according to the standards, when the end-user
|sets the DE bit, the traffic should be accounted for in EIR/Be and not CIR/Bc.
|(reference ANSI T1.606 Addendum 1 and ITU I.370).
+-------
And EIR is derived from CIR/Bc/Be.  Hence I wrote "...based on CIR/Bc/Be..."

Regards,
-james

____________________________________________________________________________
James W. Watt,     [e-mail]                   Ph: [phone]
Newbridge Networks 600 March Rd Kanata ON Canada K2K 2E6 FAX:[phone]