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

[LinkSec] RE: [802.1] P802.1ad Task Group ballot disposition





Dirceau,

The connection between the number of bits that need to be in an S-VID in the
front of any particular frame and the number of bits needed to identify all
the points of attachment to the network that receive service is not quite as
obvious as it may appear initially:

(a) any given provider bridged network that is purely bridged can have
S-VIDbits**2 service instances passing through any given bridge
- for the purposes of illustration lets assume that the network is designed
around a core of 16 full mesh connected colocation sites that connect a
number of network regions, under the rather unlikely and testing case
(because traffic tends to be more regionally concentrated than this) that
desired connectivity is randomly distributed (but dominated by point to
point which is realistic so far as my own market experience goes), then the
network capacity provided by a PVID of 12 bits is 4094/2 * 16 = 32,752
service instances. If as is likely from experience, most service instances
connect within the region (particularly to the ISPs regional drop) this
number is greater.

(b) any provider bridged network that uses other technology to connect pure
bridging regions (a good choice from a cost point of view, get the cost down
as low as possible where the numbers are greatest then use fancier
technology to connect regions of these numbers) can have 4094 * number of
connections to the core technology.

(c) where one customer distributes services to a number of subscribers,
hundreds if not tens of thousands of these subscribers can be accomodated on
one VLAN (see Norm's reply). (There is some interaction of this point with
point (b) so I mustn't double count, but it can be used to multiply the
gains of type (a) without restriction.

Mick

-----Original Message-----
From: owner-stds-802-1@majordomo.ieee.org
[mailto:owner-stds-802-1@majordomo.ieee.org]On Behalf Of Dirceu
Cavendish
Sent: Wednesday, July 16, 2003 10:20 AM
To: 'Tony Jeffree'; stds-802-1@ieee.org; stds-802-linksec@ieee.org
Subject: RE: [802.1] P802.1ad Task Group ballot disposition



Comment about "comment 44" and its response. The issue is the P-VID
space. The comment is that more bits are needed for SERVICES envisaged
by NTT's network. The response seems to imply that a too large network
is not desirable. One may have a tiny little provider network in a very
densely populated area (common in Japan big cities), and yet with
hundred of thousands of "service instances"...


Dirceu Cavendish
NEC Labs America
10080 North Wolfe Road Suite SW3-350
Cupertino, CA 95014
Tel: 408-863-6041 Fax: 408-863-6099


-----Original Message-----
From: owner-stds-802-1@majordomo.ieee.org
[mailto:owner-stds-802-1@majordomo.ieee.org] On Behalf Of Tony Jeffree
Sent: Tuesday, July 15, 2003 5:37 AM
To: stds-802-1@ieee.org; stds-802-linksec@ieee.org
Subject: [802.1] P802.1ad Task Group ballot disposition


I have placed Mick's proposed disposition of ballot comments on
P802.1ad/D1 at:

http://www.ieee802.org/1/files/private/ad-drafts/d1/802-1ad-D1-dis.pdf

username: p8021
password: go_wildcats


Regards,
Tony