On the Road to Convergence (September 01, 2006)
Last September, the London-based Economist Intelligence Unit reported on results of a global survey sponsored by AT&T that included executives at 35 large Canadian companies. Upwards of 62% said they would deploy IP networks throughout all or most of their organization by 2008.
September 1, 2006
Print this page
When the Regional Municipality of Durham, east of Toronto, opened a new regional headquarters last year, it was the ideal opportunity to rethink how the municipality provided phone service to roughly 1,200 head-office staff.
Instead of opting for a traditional private branch exchange (PBX) and a separate network running throughout the new building, the municipality decided on one Internet Protocol (IP) network to carry data, voice and ultimately video traffic.
The new building actually has two network connections to every desktop, but they do not represent separate data and voice networks, explains Troy Jones, who as supervisor of materials and office services oversees phone service in the building.
The second connection is a spare. Data and voice traffic share a single network, with a Cisco Systems Inc. IP PBX handling phone calls inside the building.
Optical fiber runs between floors, with Category 6 cabling to the desktop. “We chose it looking to the future,” says Raymond Briggs, Durham’s corporate information officer.
Over time, the municipality hopes to extend voice over IP to more offices — one other office uses VoIP now but doesn’t yet have a VoIP connection to headquarters, Jones says — and to add video applications to the IP network.
Durham is not alone. Two recent studies sponsored by telecommunications carriers and equipment vendors point to significant growth in converged IP networks.
Last September, the London-based Economist Intelligence Unit reported on results of a global survey sponsored by AT&T that included executives at 35 Canadian companies. Upwards of 62% of the Canadian executives said they would deploy IP networks throughout all or most of their organization by 2008. Globally, 60% of 236 executives surveyed had similar plans.
Then in January, International Data Corp. (IDC) released a survey sponsored by British Telecom and Cisco. It found 28% of large enterprises in Europe and the United States already have converged, IP-based networks, and forecast that number would rise to 74% within three years.
The leading reasons for switching were expected cost savings (named by 39% of respondents) and the need to replace existing PBXs (29%).
Like Durham, McMillan Binch Mendelsohn LLP installed a converged IP network because of a move. At the end of 2004, the law firm moved its Toronto office from one downtown Toronto tower to a neighbouring one. Voice over IP was still fairly rare in large enterprises at the time, says Chris Duncan, IT director at McMillan Binch, so selling the idea was tough, but “the traditional PBX seemed to be dying.”
Not having to install an entirely separate network for the 525 phones in the new office saved the firm about $150,000, Duncan says.
Since voice over IP first appeared on corporate radar a few years ago, a lot has been learned about how to do it.
One key lesson that finally seems to have sunk in is — for those that do not start with a clean slate as Durham and McMillan Binch did — the need to assess the network’s readiness for VoIP before going ahead.
Bad rap for VoIP
In its early days, many people expected it to be plug-and-play, says Brad Masterson, product manager at Fluke Electronics Canada LP in Mississauga, Ont. So networks often received no pre-qualification testing. That frequently led to problems. “Unfortunately that caused VoIP to get a bad rap,” Masterson says. As a result, some VoIP equipment vendors now insist on a network assessment before implementation, to avoid having their equipment blamed for failures caused by inadequate network infrastructure.
“We always say, start with a site survey,” says Kathy Naasz, global network integration director for AT&T Corp. “Get the facts on the table. Understand what you have.”
There are a growing number of tools that can help test the network’s readiness. For instance NetAlly, from Andover, Mass.-based Viola Networks, Inc., uses simulated VoIP traffic to predict how well a network will perform under various loads and where problems are likely to arise, says Dave Zwicker, Viola’s vice-president of marketing. NetAlly also helps with monitoring, management and troubleshooting once VOIP is up and running.
Just what makes an adequate infrastructure for voice depends on the volume of voice traffic and on what else the network must handle at the same time.
Most people in the networking field know by now that the key issue with VoIP is quality of service — unlike data packets, voice packets have to get there on time and in the right order, or the caller’s voice breaks up and the call may even be dropped.
Older networking gear may not support this. Network hubs won’t support VoIP at all, says Frank Murawski, who heads FTM Consulting Inc. in Hummelstown, Pa. — a fully switched network is a necessity — and some older switches may have to be upgraded or replaced if they lack QoS support.
Voice doesn’t demand a lot of bandwidth — around 64 kilobits per second per conversation is a common rule of thumb, Masterson says — so adding VoIP won’t necessarily stress the capacity of modern enterprise networks.
Still, multiple voice calls can add up pretty quickly. And while giving prioritization to voice packets will prevent voice quality from degrading as long as the network has enough bandwidth to handle the voice traffic, there comes a point where other traffic — the packets that don’t get priority — will start to suffer.
Murawski even questions whether combining voice and data over the same cable, which many people see as the key to realizing cost savings from converged IP networks, makes sense.
The actual cabling is less than 5% of total network costs, he says, and significant savings are possible by simply using the same switches and other network infrastructure. A number of organizations have installed VoIP networks running over separate cabling from their data networks. McMillan Binch did not do this, though, and Durham is running everything over the same cable though it has installed redundant cabling to allow for future needs.
If the IP network links multiple locations, Naasz adds, one thing to consider is whether small branch offices and retail locations have IP connections with adequate quality-of-service support. Many such facilities do not, she says.
PoE makes sense
Even if the entire network infrastructure supports QoS, Masterson warns, equipment from different vendors may handle it in somewhat different ways, and as few networks use only one vendor’s gear, that often leads to headaches.
Traditional phones draw power from the phone network, but data networks were not designed to carry electric current. One answer is to equip the phones with power adapters that plug into the wall. Aside from the minor nuisance of requiring yet another receptacle, this has the more serious drawback that when the power goes off, the phones go out.
The other answer is Power Over Ethernet, a relatively new technology for delivering the current needed to power devices like IP phones over the network cable.
This way, power can be fed from the wiring closet, where it’s practical to install an Uninterruptible Power Supply (UPS) so IP phones do not stop working in a power failure.
McMillan Binch and Durham both chose this option.
Of course, Power Over Ethernet adds another layer of complexity to the network. Seeing a need to troubleshoot power as well as data traffic, Fluke recently gave its new EtherScope Series II Network Assistant testing tool the ability to emulate powered devices and measure direct-current voltage on the network.
While McMillan Binch Mendelsohn’s Toronto location is the firm’s only office using VoIP internally today, Duncan says the firm is reviewing the phone system in its Montreal office. Voice traffic between the two offices already travels over a wide-area IP connection, which provides four-digit dialing between the offices and eliminates long-distance charges, Duncan
Replacing Montreal’s PBX with VoIP would allow the Toronto and Montreal systems to back each other up — a benefit McMillan Binch understands well after suffering a problem that left its Montreal office without voice mail for about a week this spring.
The challenges for VoIP on the wide-area network are similar to those within the LAN, revolving around quality of service. Telecommunications carriers are moving to Multi-Protocol Label Switching (MPLS) to address quality-of-service needs.
Bell Canada provides MPLS to all major cities across the country, says Paul Rowe, vice-president of enterprise marketing at the Montreal-based carrier. This offers three priority levels for network traffic, increasing to five by the end of this year. Customers using all five levels will typically divide traffic into voice, video, high-priority data, standard data and low-priority data, he explains.
MPLS also supports multicasting, or efficient transmission of the same video stream to many locations, which Rowe says will be useful for delivering corporate video presentations to multiple locations within a business.
And, Naasz says, MPLS minimizes compatibility issues because it can interact with many types of endpoints.
The connection between internal VoIP systems and the public telephone network is in the midst of a leap forward with the introduction of IP trunking, which replaces the conventional trunk connection from the corporate phone system with an all-IP link.
This means that as long as it has access to a good-quality IP connection, an IP PBX can be connected to the phone network in a remote location, says Robert Quance, general manager of MCI Canada, Inc., which launched a local IP trunking service in June. For instance, an IP PBX in Toronto might be connected to the network in Montreal so calls in the 514 area code are local.
Because IP trunking uses the Session Initiation Protocol (SIP), which is designed to handle all types of traffic including data and video, it will make it easier to build integrated applications.
Interest in video growing
Standards and protocols need to be finalized and applications developed to take advantage of this before IP trunking really takes off, says Warren Shiau, lead analyst at Toronto-based consulting firm The Strategic Counsel.
But IP trunking appears poised for growth. MTS Allstream launched IP trunking service in June. Bell plans a launch by the end of this year, Rowe says.
Meanwhile, Durham’s headquarters are equipped with digital security cameras that can be monitored remotely, Briggs says, and some municipal staff have television sets to allow them to watch council and committee meetings in their offices. Currently, these use a separate network, but the municipality plans to transfer the video traffic to its IP network.
“We wanted to make sure that the voice and data were as solid as a rock” before incorporating video on the same network, Briggs says, but “it’ll be a very simple cutover.” The transition should come fairly soon, he says.
McMillan Binch Mendelsohn runs videconferences over the IP link between its Toronto and Montreal offices, and Duncan says the demand is strong. “I’m actually quite surprised at how much it’s used — we easily have one or two meetings a week that are asking for videoconferencing.”
Though not as widely adopted as voice over IP, video over IP is drawing an increasing amount of interest, Naasz says. “We think it’s gaining traction,” Rowe agrees, noting that financial institutions are among the early adopters.
One obvious application is videoconferencing. Naasz says the motivation is not so much that companies believe reduced travel costs will pay for implementing videoconferencing as that, once the IP network is in place, video is another application that can be added fairly easily.
No longer do businesses need complex, expensive videoconference bridges to conduct videoconferences among multiple locations. “IP has enabled that application,” Naasz adds.
Other uses for IP video include security and corporate television as an internal communications tool.
The issues IP video presents are not much different from those that VoIP raises, Masterson says. The main difference is the bandwidth requirement: One video stream needs about 384 kilobits per second, versus 64 kbps for voice.
Duncan says the impact on McMillan Binch’s 10-megabit-per-second IP link between Toronto and Montreal isn’t noticeable. “I think the network can handle it,” Naasz says — it’s simply a question of assigning the right priorities to data, voice and video packets. After all, success with IP is ultimately a question of getting the underlying technology right.
Grant Buckler is a Kingston, Ont. freelance writer who specializes in IT and telecommunications issues. He can be reached at email@example.com.