From: Mas Kato (loomis_towcar@xxxxxxxxxxxxxx)
Date: Sun Oct 07 2001 - 00:34:06 GMT-3
[demime could not interpret encoding binary - treating as plain text]
Thanks to all that have responded. These technologies are all documented on CCO
, but it's nice to validate what's usually "pre-digested" before it gets to me.
DPT indeed seems to be SONet-like, with added robustness that appears to addres
s some of the challenges plain-old SONet provisioning and recovery can pose, am
ong other things. Being based on Cisco's proprietary Spatial Reuse Protocol (SR
P), it probably will light more dark fiber MANs than anything else for now, but
Cisco says they've submitted it to the IEEE for consideration as a standard (8
02.17 Resilient Packet Ring).
The buzz I've been hearing over the last couple of years over POS certainly see
ms to have developed into a groundswell, at least in the core/backbone sector.
The state-of-the-moment with Cisco 7xxx family OC-12 support is kind of interes
ting and telling:
-DPT OC-12 is available on the 7200 ($)
-DPT and ATM OC-12 on the venerable 7500 ($-$$)
-POS OC-12 on the 7600 ($$$) (with ATM OC-12 just recently announced)
Regards,
Mas
>Date: Sat, 06 Oct 2001 10:09:34 -0700
> jonatale@earthlink.net Mas Kato <loomis_towcar@speedracer.com>CC: ccielab@gro
upstudy.com
> Re: Off-Topic: OC-12 Survey
>I think DPT is a ring based technology, the other two are [physically] p2p. Th
e driving force I imagine is that allot of existing fiber/SONET is laid (someth
ing I need to get) out as rings, or more specifically counter rotating rings (l
ike FDDI); this provides greater protection against
>fiber breaks. But I think DPT scrapped allot of the SONET overhead stuff that
never really got used (like when FR took over X25). I hope this helps -- I know
there are allot of "I thinks" here, but you can do the foot work and verify/di
spute my claims (I'd be happy to know what you find
>if you care to write back. Thanks, and good luck.
>
>Mas Kato wrote:
>
>> [demime could not interpret encoding binary - treating as plain text]
>> Sorry for the off-topic post, but I've heard from other forums and wanted to
hear from others working "where the rubber meets the road."
>>
>> The Cisco 7xxx line supports at least three modes of transport at OC-12 rate
s:
>>
>> DPT - Dynamic Packet Transport (proprietary, SONet-like)
>> ATM - UNI
>> POS - Packet over SONet
>>
>> I was just wondering what the state-of-the-moment preferred transports are w
hen NSPs need to lob in an OC-12 into an enterprise or medium-to-large POP. At
one point in time ATM OC-12c was the way to go, but there has certainly been a
lot of buzz revolving around POS. What about DPT?
>>
>> I'd be curious to know what trends you all are seeing out there...
>>
>> Thanks in advance-
>>
>> Regards,
>>
>> Mas
>>
>> Mas Kato
>> https://ecardfile.com/id/mkato
>>
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