Metro WDM: What Carriers Think

Early in November 2002, Light Reading's series of reports on metropolitan networking took a special turn when we polled and received more than 220 responses on carriers' attitudes toward, and plans for, metro area Wavelength Division Multiplexing (WDM).

Our purpose was to find out how well our first Webinar and report on metro WDM matched the reality of carriers' plans. (For our earlier report, see Metro DWDM; click here to view the archived Webinar).

The full results of the survey are published in this report, and they may surprise you. Despite concerns that matched those unearthed in our earlier report, service providers are clearly interested in using WDM, including both dense WDM (DWDM) and coarse WDM (CWDM). What's more, their biggest disincentives tally directly with what they see as the biggest motivators for deploying the technology.

For example, of the total group that responded to Light Reading's survey, most respondents said high cost was a leading discouragement. Nonetheless, more than 50 percent plan to deploy new or additional DWDM/CWDM gear, most within the next 12 months, and they indicated their reasons were cost-related: The prospect of cutting operating expenses was the highest-ranked of several factors affecting carriers' plans. Respondents also want to use WDM to offer new services and provision them quickly.

These results imply that if vendors produce products that meet carrier requirements, they'll be adopted.

This report gives a look at the details, including the specific features and functions carriers want to see in their DWDM gear:

— Mary Jander, Senior Editor, Light Reading
www.lightreading.com

Want to know more? The big cheeses of the optical networking industry will be discussing Metro DWDM at Lightspeed Europe. Check it out at Lightspeed Europe 02.

Light Reading's carrier survey of metro DWDM was taken by 221 respondents, about 75 percent of whom indicated they were service providers in the traditional sense of the term.

Invitations to fill out the questionnaire were sent to a selected group of readers via email. The questionnaire was posted for several days and closed on Thursday, October 24, 2002.

Respondents came from a range of different types of service-provider companies. The strongest representation came from IXCs and CLECs, with a smaller percentage of incumbent LECs and RBOCs. Interestingly, few cable operators participated.

Geographically, we heard from a range of different regions, with the most representation coming from the U.S., Western Europe, and Asia/Pacific.

A variety of staff positions were represented, with well more than half on the technical and engineering side.

When it comes to current deployments, nearly three quarters of respondents reported that less then 30 percent of each of their metro networks now employs WDM technology.

Existing metro infrastructure WDM deployments mostly involve either a small number of channels or at least 12 channels.

When it comes to the size of systems used in enterprise deployments – that is, to provide services to business customers – the trend is even stronger.

One possible reason for the gap in channel usage has to do with the kinds of services for which carriers and their customers are looking to WDM. Right now, for instance, many corporate customers look to WDM for LAN extension or storage networking, according to Brian McCann, VP of marketing at ADVA AG Optical Networking (Frankfurt: ADV), which makes metro DWDM gear. One application takes lots of bandwidth, the other does not.

"Storage area networking [applications], like disaster recovery... are extremely bandwidth-intensive applications that can take dozens to hundreds of channels," McCann says. But LAN extensions across a metro area tend to be just a few Gigabit Ethernet links between multiple locations around different facilities.

So what do carriers want from WDM technology – and what might hold them back from using it? To discover that, we asked survey respondents first to rate the top motivators for deploying DWDM/CWDM in their metro networks, using a rating scale from 1 to 5. Here are the answers we got:

Table 1: How would you rate the importance of the following motivators to deploying DWDM/CWDM in your metro networks? (Rate 1-5, with 5 being most important) Respondents = 159

Clearly, there's not much variation in the rankings; all fell within one point. Still, it's interesting to note the tie between offering new services and speeding up provisioning. It also appears that the avoidance of new fiber rollouts, once the main marketing pitch for DWDM, isn't the chief factor in these responses.

We also asked carriers to tell us the kinds of metro services they're interested in provisioning with WDM, again using a rating scale of 1 to 5. Here's what they told us:

Table 2: How would you rate your interest in offering the following high-bandwith services over DWDM/CWDM networks? (Rate 1-5, with 5 being highest interest) Respondents = 156

Again, there isn't enough variation among rankings to indicate a real hierarchy of service preferences. Noteworthy, perhaps, is the overall popularity of LAN interconnect with carriers that are interested in using WDM to help business customers extend their corporate networks.

We also were interested in knowing what's holding carriers back from deploying WDM in their metro networks. Following are the key discouragement factors governing their reluctance to buy WDM gear. Not surprisingly, cost is the biggest dealbreaker.

Table 3: Table 3: What's discouraging you from deploying DWDM/CWDM in your metro networks? (Rate 1-5, with 5 being most discouraging) Respondents = 177

A key part of Light Reading's carrier survey on metro WDM was to find out service providers' plans for the technology. First, we asked respondents to tell us their company plans in general terms. NOTE: We were asking not only about the plans of the carriers that have no DWDM gear installed, but the plans of those that have it installed and are looking to add more capabilities (or perhaps not to add them).

Following is the response we received:

The good news here is that nearly 50 percent of respondents told us they plan to deploy DWDM within a year, if not sooner. Another 22 percent said they plan to deploy it sometime in the future. Depressingly, 13 percent have no plans and 16 percent remain unsure.

While the effects of the telecom downturn can't be discounted, it's important to note the large percentage of respondents claiming to simply not know how their company's plans may unfold. A savvy marketeer might say this is a great opportunity to educate undecided folk on the benefits of metro WDM!

When we asked respondents to tell us what they are currently spending and plan to spend next year on metro DWDM, we got responses that seemed to reflect the uncertainty of the above responses. But there also appears to be a lot of interest in the technology. Note that the percentage of folk planning to spend between $100,000 and $5 million is greater for 2003 than for this year.

So what kinds of features and functions will help carriers determine what WDM equipment to buy? That's the question that may hold at least one key to unlocking the potential of the technology in metro networks.

To get answers, we first asked respondents to rate the importance of several issues related to WDM equipment:

Given the caveat about a lack of differentiation in ratings, it's still interesting to note the relative importance of these key features. All of them relate in one way or another to the basic list of motivators for using WDM listed earlier. Equipment cost, for instance, goes with the cost cutting and ease of provisioning carriers mentioned elsewhere in the survey.

Other features contribute to these motivators as well. Scaleability, for instance, enables the addition of new services without having to go through the operating expense associated with lots of manual adjustments and added capital expenditures. Protocol transparency and network management aid ease of use and speed of provisioning.

It's interesting that supplier stability is last on the list. Apparently, carriers would be willing to bank on startups if the cost and feature list were right.

Getting even more specific on equipment characteristics, we asked respondents to rate a laundry list of key functions contained in many DWDM and CWDM products. Here's what came back:

Topping the wish list is DWDM, automatic protection switching, and integrated Gigabit Ethernet capabilities. These results aren't surprising. Metro services are increasingly becoming Ethernet-driven, and it looks as though the trend is likely to continue. Likewise, the importance of protection in metro gear is a constant concern, as reflected in ongoing efforts such as Resilient Packet Ring aimed at bringing Sonet/SDH backup features to packetized networks.

What's more, if scaleability is a key concern, it's no surprise that DWDM capabilities are wanted. It looks as if carriers want to start with smaller systems, such as 8-channel ones, and augment them as demand increases without having to switch platforms.

Bottom line? It seems plain that most respondents to our survey are interested in using WDM for metro services, but they're held back by several concerns, predominantly cost and a concern that demand won't match capacity.

We can't discount the effect of the telecom downturn on carriers' views. But it's also clear that many of them are looking to WDM to help solve some of the problems of cost and complexity that are hindering their revenue-generating capabilities.