Optical/IP Networks

Cisco's CRS-1 Goes Optical

Some of Cisco's ongoing plans for the optical network are getting implemented in the CRS-1 core router, as the company today plans to introduce new DWDM optics for the box as well as support for Cisco's version of generalized MPLS (GMPLS).

Cisco is announcing the developments in conjunction with its annual analyst conference, which begins tomorrow in Santa Clara, Calif.

Buried in the announcement is the fact that (Nasdaq: CMCSA, CMCSK) has become a CRS-1 customer. The cable operator hasn't formally announced it's using the router, but an official is quoted in Cisco's release saying Cisco's new DWDM interfaces represent "key reasons for our selection of the CRS-1."

"We believe the CRS-1 can be the foundation of our NGN strategy into the next decade," says John Leddy, Comcast vice president of network and transport engineering, in an LRTV video produced for Cisco. (See IP Routing for Next-Generation Networks.)

Comcast's decision isn't that much of a surprise, as the cable operator is building a next-generation IP network that already incorporates Cisco's BTS 10200 softswitch and Call Session Control Platform. (See Cisco's CRS-1 Gets Edgy.)

Cisco's principal announcement for the CRS-1 concerns a pair of cards with high-speed DWDM optics. This opens the possibility of the box launching IP traffic onto DWDM wavelengths directly, bypassing the Sonet layer.

One card sports a tunable, single-port, 40-Gbit/s interface that can connect to a 10-Gbit/s optical infrastructure. Cisco previously demonstrated a 40-Gbit/s interface that used StrataLight Communications technology to run the traffic on a 10-Gbit/s optical network; officials wouldn't comment on whether this new card uses the same technology. (See StrataLight Powers Cisco's OC768.)

The other card provides tunable WDM optics for 10-Gbit/s Ethernet, using digital wrapper technology, per the International Telecommunication Union (ITU) G.709 standard, to link the traffic to Sonet operations, administration, and maintenance (OAM) that Ethernet wouldn't normally have.

IP-over-DWDM is something Cisco has talked about for a while. The idea complements Cisco's strategy to use the same pluggable optics on its routers and on optical equipment like the ONS 15454. (See DWDM Goes Pluggable.)

The idea was kicked around circa 1999 as a means of "collapsing" the network, removing a layer of Sonet equipment to save costs. DWDM vendors such as Ciena Corp. (Nasdaq: CIEN) would seem to have the most to lose in such cases. But Ciena says it's ready for the trend once it starts, as equipment like that company's CN 4200 can be used to put different service types onto DWDM wavelengths. (See Ciena Claims DWDM Coup.)

"You still need that WDM network to carry your traffic," says Vinay Rathore, director of segment marketing for Ciena. "The DWDM thing they've gotten rid of is just the transceiver, not a separate box."

Rathore also contests the notion that entire systems would be removed from the network this way. In many cases, IP-over-WDM just amounts to moving a transponder from an optical box into the router, he says.

GMPLS redux
As for what to do with IP-over-DWDM, Cisco is adding to the CRS-1 a new version of GMPLS, the set of protocols aimed at letting routers request bandwidth from the optical network.

The hangup with GMPLS was that carriers didn't want to reveal their optical networks to other carriers' routers. So, GMPLS fragmented into two models -- "peer," where routers get full visibility into the optical network, and "overlay," where routers can place bandwidth requests but don't get to see the topology of the optical network. (For a history lesson in GMPLS, see the 2002 report, Optical Signaling Systems.)

Cisco has created a compromise called the Segmentation Model of GMPLS, or S-GMPLS. The optical network owner gets control over how much visibility routers get, with the option of giving the router full visibility.

"You can think about it like service providers that are peering -- you can advertise routes," says Mike Capuano, a Cisco senior marketing manager.

GMPLS is represented by at least a half dozen standards from multiple groups, including the Optical Internetworking Forum (OIF), which is pitching an overlay model called Automatic Switched Optical Networks (ASON).

Cisco is adding S-GMPLS to the fray, having filed an Internet Engineering Task Force (IETF) draft in July titled Operational, Deployment, and Interworking Considerations for GMPLS.

S-GMPLS combined with IP-over-DWDM creates this scenario: Cisco's CRS-1 could connect directly to reconfigurable optical add/drop multiplexers (ROADMs), such as Cisco's 15454, with the router able to assign wavelength adds and drops on the ROADM. "In general, to have a whole solution like that from a single vendor is really valuable," says Scott Clavenna, Heavy Reading chief analyst.

One question facing S-GMPLS is whether carriers are that interested. GMPLS was intended as a way to create a dynamic optical core, with wavelengths being brought up as routers needed them -- but carriers still don't show much interest. "They still think of the core as more of a static thing," Clavenna says.

Cisco officials say they're hearing demand for GMPLS or similar functions, pointing to GMPLS trials conducted in June with . (See Cisco, NTT Demo GMPLS.)

— Craig Matsumoto, Senior Editor, Light Reading

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lite_network 12/5/2012 | 4:10:30 AM
re: Cisco's CRS-1 Goes Optical CRS-1 essentially makes the case for the bigger box and fatter pipes. How many such boxes can Cisco sell is a key question. This issue seems to be the same one that Ciens faced with the Core-director when sales dried due to virtually all opportunities exhaused.

Some of the largest NGN (combined triple-play) networks do not require such scale. A T-series is more than sufficient for 95% of large core POPs

40G has some serious optical layers issues. PMD becomes a key concern in any kind of traditional NDSF fiber. 4*10G with optical WDM is a very good alternative for many carriers

Cisco seems to have admitted with its new XR operating system that the older IOS cannot cope with the high reliability requirements of new infrastructure devices.
SqH2O 12/5/2012 | 4:10:30 AM
re: Cisco's CRS-1 Goes Optical I wonder what the deployment of the Commcast Cisco/Nortel network looks like. Nortel's stuff will send signalling to Cisco's equipment??? I have a similar deployment but on a microscopic scale. My Cisco and Brocade gear see my Nortel equipment as a piece of wire. Both are humming perfectly.

The two systems are highly abstracted and for good reason. We've tried mixing our equipment's functions once (IPoEoSDHoDWDM) with disastrous results!
turing 12/5/2012 | 4:10:29 AM
re: Cisco's CRS-1 Goes Optical More to materialgirl's point - how can one give evidence of something that isn't? I mean if they don't have deployments, what would evidence be? A list of every carrier in the world the CRS isn't deployed in?

Shouldn't it be on Cisco's shoulder to produce evidence they are truly deployed and making revenue from it? And I mean more than a lab at their whipping boy comcastic. (really, comcast is almost a subsidiary of cisco in terms of their buyer/seller relationship)
ozip 12/5/2012 | 4:10:24 AM
re: Cisco's CRS-1 Goes Optical As a previous poster stated, it takes time to win and build core networks. However, what rock have you pundits been hiding under, havenGÇÖt you noticed IP-TV and new forms of internet video distribution and the new hardware and operating systems that have been and will be launched this year to capitilize on this trend. The broadband users average consumption of bandwidth could easily multiply 1000x over the next three years. Multicast, an area that Cisco highlighted in the CSR-1 release, could become the single most important bandwidth management technology. However, the need for increased capacity is a given.

As for optical integration, GÇ£Alien WavelengthsGÇ¥ (as they are called) are already carried in the metro by a number of optical vendors, improved interoperability and management only make sense.

Core Routers are long-term investments. How long has the 12000 been around? Some made the same cost/deployment assertions, IGÇÖm certain they are not the same folks this time around..

melao 12/5/2012 | 4:10:24 AM
re: Cisco's CRS-1 Goes Optical "40G has some serious optical layers issues. PMD becomes a key concern in any kind of traditional NDSF fiber. 4*10G with optical WDM is a very good alternative for many carriers"

I strongly agree. Specially if you think how high the Channel Count is nowadays on DWDM systems!!

reoptic 12/5/2012 | 2:51:51 AM
re: Cisco's CRS-1 Goes Optical Still pitching this for exotic applications like 40Gb and S-GMPLS and IP over DWDM. These are low volume. Make for good carrier announcements but poor revenues and profits.

How many carriers have actually deployed networks of scale, and not just research and science fair stuff, with CRS-1?
Honestly 12/5/2012 | 2:51:48 AM
re: Cisco's CRS-1 Goes Optical Gee, imagine that LRTV producing Cisco Videos, oh all of the sucking up by writers is cooincidence. Nice to also see former Juniper product guy Mike spin a Cisco story. Funny, he knows how screwed up their architecture is, Cisco bought him as they try to do with many Juniper guys, but the top Juniper guys stay and they get the best from Cisco because Cisco stock is DEAD.

CRS hasn't won DICK. Hey John, how are you really doing at a real carrier like BT. Oh, no comment. HA
Merovingian 12/5/2012 | 2:51:47 AM
re: Cisco's CRS-1 Goes Optical
40G links is simply a matter of time, remember when OC-192 was first introduced? Is it still considered exotic?

>How many carriers have actually deployed networks >of scale, and not just research and science fair >stuff, with CRS-1?

How about these that are underway? C&W, CT, Telstra, Swisscom etc..

Core SP networks don't get built out overnight I think we all realize.
Pete Baldwin 12/5/2012 | 2:51:42 AM
re: Cisco's CRS-1 Goes Optical Hey -- for the folks who've been posting that the CRS-1 isn't all that successful: Give us specifics! Given ammunition, we're more than happy to be critical of the box.

E-mail is always on: [email protected]

Phone's even better: (415) 321-3750 x.28
materialgirl 12/5/2012 | 2:51:38 AM
re: Cisco's CRS-1 Goes Optical Craig, as a Wall Streeter I can say one thing. Any product that was introduced with this much fanfare is never, but never, mentioned in CSCO conference calls. That is not a great sign. It "should" be important enough to drive results in some manner, and therefore require comment. The silence is deafening.
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