[c-nsp] Cisco ONS experience

[Matthew Crocker]

The ONS platform is an extremely solid, stable SONET platform.  It is  
NOT a 'media converter' nor is it a WAN/ATM system.    It can handle  
DS-1,DS-3,OC-n (3,12,48,192) and FastEthernet/GigEthernet.     
Everything inside the SONET ring is known as an STS,  an OC-48  
contains 48 STS-1s,  Each STS-1 is a DS-3 + SONET overhead.  An OC-3  
is 3 STS-1s which can either be 3 DS-3s or 155mbps (OC-3c).   With  
the ONS you can map circuits around the ring and pick them up on  
other nodes.   You can map an OC-3c ATM circuit onto the ONS and pull  
it off as an OC-3c ATM circuit at the other end.  You cannot take an  
OC-3c ATM circuit and pull it off as 3 DS-3 ATM circuits,  nor can  
you map ATM to Ethernet.    With Ethernet the ONS does have the  
ability of terminating Ethernet into STS-n and pick it up at several  
points around the ring.

For example:  We have a 4 node, OC-48 15454 ring.  I've mapped 12  
STS-1s (OC-12c) into a 'metro ethernet'  Each node has a GigE  
interface into this 622mbps 'metro ethernet'.  I can pick up VLANs on  
one gigE and deliver them to another gigE in another node.  All  
Ethernet traffic shares the 622mbps OC-12 inside the ring.

With the right cross connect card (XC-VT or XC-10G) the ONS can act  
as a 3/1 DACS system to groom T1s (known as VT1.5 inside a SONET  
ring) on multiple Channelized DS-3s to maximize router ports (there  
are better ways of doing this BTW).  The ONS cannot see DS0's so it  
cannot do 3/1/0 DACSing

The ONS was originally from CERENT before Cisco bought it.    
Extremely stable, 'carrier grade' blah blah blah.    The CERENT guys  
went off to start a new company named Calix that has a SONET box  
called the C7.   The Calix C7 is more of a 'do everything' box as it  
can see raw packets inside circuits and do stuff on the packets.  
Kinda like a SONET/ATM/Ethernet switch.  I don't have any direct  
experience with the C7 although I may in a couple months for some  
gPON deployments.  If it is anything like the CERENT 454 I'm sure it  
will be impressive

-Matt



On Jan 5, 2006, at 9:20 AM, Kim Onnel wrote:

> Gentelmen,
>
> We're a mid sized ISP, surprisingly we havent heard of ONS and similar
> devices until recently, the quick intro we were given is that it will
> connect different medias to overcome WAN problems, example, connect  
> two
> ethernet interfaces through WAN with ATM uplink,
>
> I'd like to know peoples experience with these devices, is there  
> similar
> non-cisco trusted devices, are they stable enough, any known  
> problems ?
>
> Thanks
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--
Matthew S. Crocker
Vice President
Crocker Communications, Inc.
Internet Division
PO BOX 710
Greenfield, MA 01302-0710
http://www.crocker.com