Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

RE: [RPRWG] Is spatial reuse of A0 traffic possible?




Fredrik,

I think that the answer is "maybe". There are some limited cases where it is both feasible and within the standard to do so. But, in the general case, it is not easy to accomplish.

jl

-----Original Message-----
From: owner-stds-802-17@xxxxxxxxxxxxxxxxxx
[mailto:owner-stds-802-17@xxxxxxxxxxxxxxxxxx]On Behalf Of Fredrik Davik
Sent: Monday, December 22, 2003 2:25 AM
To: stds-802-17@xxxxxxxx
Cc: steing@xxxxxxxxx; myilmaz@xxxxxxxxx; nuzun@xxxxxxxxx
Subject: [RPRWG] Is spatial reuse of A0 traffic possible?



Clause 1.10 claims that spatial reuse of A0 traffic is possible, while
section 10.5.2.2.1 sums each station's individual demand for A0 traffic
when calculating the reserved bandwidth on a ringlet, regardless of
where the individual stations will send A0 traffic.

Is there a conflict here?

Details to clarify the question are provided below...

In clause 1.10 Spatial reuse second paragraph on page 39, lines 9-11
there is a statement:

...There are restrictions on this form of bandwidth reuse, in that some
portions of the classA bandwidth (called subclassA0, see 6.3) can be
safely reused on non-overlapping segments, but cannot be reclaimed by
other service classes.

In clause 10.5.2.2.1 Computation of total unreserved bandwidth, page
334, the function ComputeTotalUnreservedRate() iterates through the
topology database entries for every station on a ringlet, reserving
an amount of bandwidth which is the sum of every station's individual
demand for reserved bandwidth.

My question is divided in 2 parts:

1. Is spatial reuse of A0 bandwidth possible?

2. What is the relationship between the ringlet{0,1}ReservedBW value
   it sends out in its station bandwidth ATT (clause 10.5.2) and the
   setting of the station's addRateA0 shaper setting? 
   (addRateA0(ringletX) == ringletXReservedBW)?

My understanding of the current draft (3.0) is that a station is only
allowed to send the amount of A0 traffic on a ringlet as configured by
its addRateA0 shaper setting. Also, it seems like the total reserved
rate on a ringlet is the sum of each station's individual demand for
A0 traffic.

if (addRateA0(ringletX) == ringletXReservedBW), then I don't see how
it is possible to have spatial reuse of A0 traffic..

Best Regards, 
Fredrik 
---------------------------------------------
Fredrik Davik
                 Phone:       +47 67 82 83 88
                 Mobile:      +47 45 24 91 88
                 Fax:         +47 67 82 82 01
                 Switchboard: +47 67 82 82 00

mailto:bjornfd@xxxxxxxxx

http://heim.ifi.uio.no/~bjornfd
http://www.simula.no/people_one.php?people_id=22

Simula Research Laboratory
P.O.Box 134, Lysaker
N-1325 Lysaker
Norway