NSN, Juniper pick up the IPoDWDM baton

This article originally appeared on fibresystems.org.

WDM NICE, 2009 — Nokia Siemens Networks (NSN) and Juniper Networks seem to be forging an ever closer relationship. Having recently joined forces to sell Carrier Ethernet equipment, the pair are now working together to integrate IP routing with WDM equipment — a concept called IP-over-DWDM or just IPoDWDM.

This development aligns Juniper’s strategy more closely with that of Cisco Systems, which originally introduced IPoDWDM about three and a half years ago.

Juniper is bringing IP router expertise to the party, while NSN is providing its optical transport solution, and operational systems for both technologies. The aim is “to enable seamless interworking between IP and optical networks to improve network efficiency and reduce operator opex”.

Simply put, a long-distance DWDM laser on a router card injects a signal into the WDM system, which travels to the router at the other end of the link. “Often people refer to this as an alien wavelength; what we’re trying to do is make this into a friendly wavelength,” explained Stefan Voll, head of solution sales management at NSN.

The partners have already demonstrated how this might work. The Norwegian research network operator Uninett has successfully tested a coloured OTU-2 interface on a Juniper T-series core router connected to NSN’s hiT7300 WDM platform, and managed by the latter’s Transport Network Management System (TNMS).

This approach generates some capex savings, because the short-reach, “grey” optics that would normally connect the core router to the WDM system are eliminated. “In the grand scheme of things that [capex saving] might be a relatively small amount, but at 40G and 100G the savings could be more significant,” Voll pointed out.

However, the prime motivation for IPoDWDM is to streamline the network in order to save operational costs. In an IPoWDM system, there would be fewer components to fail, monitor and manage, and there would be some rack-space and power savings, according to Voll.

Even greater opex savings should be possible as a result of integrating the IP and optical transport layers.

In the short term, the idea is to give the router more visibility into the optical layer to provide more options for protection and restoration. “There are two trends in the IP/MPLS world, and they are both contradictory,” explained Voll. “The first is the increasing focus on service-level agreements — more mission critical applications are being carried on IP/MPLS. The second is the move towards plain Ethernet instead of SONET/SDH interfaces, and the resultant loss of valuable troubleshooting information. If the carrier has access to the Layer 1 view, which they would have with IPoDWDM, then they can take remedial action to prevent packet loss.”

In the medium term, NSN/Juniper are targeting a single management and service provisioning platform for Layers 1, 2 and 3. Today, implementing new IP services requiring additional optical connectivity is a cumbersome process, because IP and optical transport are often managed by different departments using different management systems, and may even have different network operations centres. Unifying those departments will ease this problem — if carriers are willing to take the plunge.

Cisco welcomed the NSN/Juniper combo to the IPoDWDM party. “I was very excited by the announcement,” said Russ Esmacher, senior product line manager for Cisco’s optical transport business unit, in response to a question from the audience on Cisco’s reaction. “It’s not just Cisco anymore. Now the whole industry is starting to discuss IPoWDM to see if it’s a good fit with their networks.”

Esmacher suggested that this development could also lead to interoperability between the two core router vendors. That’s because for IPoDWDM to work in the first place, the properties of the optics on the router port must be very well characterized, and be integrated into the DWDM system’s planning and design tools, so that it can be managed in exactly the same way as a standard transponder. Now that’s what I call friendly!

Reproduced with permission. © Institute of Physics and IOP Publishing Ltd.