Subject: RE: response to ITU-T SG13

From: [email-masked]
Date: Mon, 15 Apr 2002 17:21:55 +0100

Giles Heron wrote 15 April 2002 14:57
<snipped>
> 
> so you're effectively saying that in order to apply OAM at a higher
> layer trail you need strictly CO trails at all lower layers?

NH=> There are 3 basic network types:
-	cnls
-	co pkt-sw
-	co cct-sw
Each has a generic 'network solution' irrespective of particular technology
across data/control/management-plane facets.  Below IP all technologies are
either co pkt-sw or co cct-sw.  What do you think IP routers are connected
with across the WAN?.....physical wide area connectivity must ultimately use
a CO technology, eg SDH/SONET, PDH, WDM, OTN.  So, assuming we can manage
all these layers independently, the trite answer to your question is 'yes'.

regards, Neil

---

From: Giles Heron <[email-masked]>
Date: 15 Apr 2002 18:02:16 +0000

Hi Neil,

> all these layers independently, the trite answer to your question is 'yes'.

Not all technologies below IP are CO.  What about the most common link
layer for IP - Ethernet?

Sure, Ethernets run over wires (which are inherently CO).  But then what
about 802.11b wireless LANs?  Not much CO going on there AFAIK.

But yes, as someone who connects IP routers for a living, I am well
aware that in the wide area IP runs over CO technologies ;-)

At any rate, your "yes" answer gives me cause for concern.  If you
require strictly CO trails (i.e. TE) at *all* lower layers in order to
use OAM at a higher layer then OAM would seem to have quite limited
utility?

Giles

-- 
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Giles Heron    Principal Network Architect    PacketExchange Ltd.
ph: +44 7880 506185              "if you build it they will yawn"
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