DWDM interconnects

Tue Jan 7 00:19:15 UTC 2003

It was something that came up years ago on where would peering go if 
traffic levels kept the growth rate exponential.

Problem is that while the equipment vendors use "standard" channel 
frequencies.  The implementation (ie protocols)  is completely 
different.  While both companies may have DWDM equipment they must 
hand off standard 1310nm.

While working on designs for Bellsouth Mix, we really wanted to 
extend DWDM directly to the customers.  At the very least we 
hypothesized that with a colo we could see a benefit to DWDM 
cross-connects (ie intra-node, hair-pinning) however we quickly ran 
into the vendor issue.

If you approach the vendors, the incumbents have no desire to open up 
their technology since they feel they already "own" the customer 
base.  New companies such as Sycamore or ONI have to find ways to 
reverse engineer without breaking the law or getting sued.  They then 
run the risk of having this engineering break during an software 
upgrade to the incumbent's equipment.

Sycamore's fix product for example shot DWDM waves using the nortel 
upgrade port. So u could use sycamore's cheaper equipment to add 
capacity to your network.  They shot at different wavelengths to the 
nortel gear and therefore caused no problems to the existing network. 
Nortel was not amused since they would have preferred to sell much 
for expensive waves.

So at the MIX even though we had DWDM throughout the network, we were 
handing off 1310 to customers.  If they did buy similar gear we could 
have extended the DWDM directly to them.  We also could allow for CNM 
(customer network management) which would allow the customer to 
control the waves they "owned" on our network.

It would seem logical at some point that carriers need to put 
pressure on their vendors to not only standardize on channels and 
frequencies but also on a common inter-vendor transport protocol. 
Treating each DWDM wave as a VPN (or VLAN) for peering btw specific 
peers makes sense for growth.

dave

At 16:04 -0700 1/6/03, Pete Kruckenberg wrote:
>How common are DWDM interconnects between networks
>(carriers)?
>
>Is DWDM considered a reliable/scalable/operable carrier
>interconnection technology?
>
>Is multi-vendor DWDM (whether internal to the network or for
>carrier interconnection) practical or sensible, especially
>for carrier/network interconnection? Many vendors proclaim
>interoperability, but does that work in the real world?
>
>Pete.

-- 

David Diaz
dave at smoton.net [Email]
pagedave at smoton.net [Pager]
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