While there are many preconceived notions about voice over IP, the reality is often different from the theory, says Thomas Dunkerley, communications manager/IT at The Seattle Times.
Washington state’s largest daily newspaper is in the thick of a company-wide upgrade to an Avaya Inc. IP telephony system that will see more than 1,200 IP phones deployed on employees’ desktops by the end of next year. As the newspaper’s telecom and data network staff work together to converge their respective environments, they’ve discovered some pleasant surprises and learned some interesting lessons.
For one, Dunkerley says, VoIP isn’t as fussy as you might expect. When the Times first got going with VoIP, it experimented with IP phones on its existing infrastructure – shared 10/100 Bay Networks hubs (with 50 per cent utilized bandwidth) and Category 3 wire. It worked fine.
“We had a phone on one hub that was averaging 60 percent to 70 per cent utilization, and you would get some pops and snaps, but nothing the person on the other end noticed,” says Paul DeWees, the Times’ network systems analyst.
Although the organization is upgrading its data network infrastructure and adding quality of service (QoS) in the process, these early tests were reassuring.
“My biggest nightmare when we started this project,” DeWees says, “was hearing a user say, ‘My phone isn’t working; what’s wrong with the network?'” So far, that hasn’t happened.
IP phones are now running on about 200 desktops at the Times’ headquarters and bureaus.
The Times began its convergence project three months ago when the time came to upgrade its Lucent Technologies Inc. /Avaya Inc. Definity G3 and G2 PBX systems. At first the company looked to upgrade the G3 PBX’s TDM central processing unit, based on Avaya’s homegrown Unix. Instead, Dunkerley went with redundant Avaya S8700s Media Servers, which are Intel- and Linux-based IP servers.
The Avaya S8700s could not have arrived a day too soon, Dunkerley says, as the system was put to work to fix a telecom problem in one of the newspaper’s bureaus.
“It saved our butts,” Dunkerley says. Immediately after the IP PBXs went in, an older Lucent G2 PBX in one of the Times’ major news bureaus crashed beyond repair. Dunkerley kick-started the newspaper’s IP telephony project one weekend by sending a dozen phones to the branch office, which accessed the S8700 over a T-1 line and eliminated the need for a remote office phone switch. The remote office’s change to VoIP almost went unnoticed, according to Dunkerley.
“On Monday, everyone just said, ‘Oh cool, new phones,’ and went to work,” he says. “From that point on, we’ve been rolling out a dozen phones or so per week.”
The S8700 servers run the same MultiVantage call control operating system as the TDM-based PBX; they also fit into the existing cabinetry and use the same digital trunk cards and public switched telephone network interfaces as the old system. This lets the newspaper gradually deploy Avaya IP phones without disrupting users with older digital Avaya handsets.
While the cost for upgrading to the IP-based PBX was about the same as a standard Avaya PBX upgrade, Dunkerley says the Times expects to see savings in WAN costs, productivity gains from converged voice/data applications, and simplified network administration. Adds, moves and changes also will be simplified, as end users can log on to any IP phone on the network and have their phone extension and preferences moved to that phone.
Priorities are set
The new VoIP traffic will be riding a revamped data network infrastructure anchored by three big Cisco Catalyst 6509 switches. These Catalysts link to a distribution layer of 40 Catalyst 3524 switches, located in the company’s computer room. From there, DeWees is in the process of upgrading the mix of wiring closet hubs to Avaya Cajun P330 switches, which will be the only non-Cisco layer of network.
The Cajun switches will give every desktop a switched 10/100M bit/sec link with QoS support and provide electrical power to the Avaya IP phones over a Category 5 wire. The Cajun switches will be connected to an uninterruptible power supply so the inline power will ensure that the phones stay up during a power outage.
While the Times has gotten by so far with rolling out IP phones on its existing data network, “we still want to do QoS,” DeWees says. “We want to build the network correctly from the ground up so that it’s ready for whatever we throw at it in the future.”
IP voice packets will be segmented and prioritized on the network in two ways, DeWees says. QoS will be set with 802.1p packet prioritization, a Layer 2, four-level queuing technology where packets generated by the Avaya phones and the S8700s will be given Level 1 priority, while other traffic will be tagged as Level 4. Additionally, all IP phones will be grouped on their own virtual LAN, using 802.1Q VLAN tagging, and assigned to a separate voice subnet. This will let the staff isolate voice traffic from data for troubleshooting and traffic monitoring purposes.
DeWees says the simplicity of the QoS mechanisms on the Avaya VoIP gear helps in the Times’ multivendor converged network. “The most essential parts of the technology – IP, Ethernet and QoS – are so standardized we haven’t found any interoperability issues between the Avaya phones and the Cisco switches so far,” he says.
In addition to the extra traffic the VoIP system will generate, the IT staff realized early on that the IP phones will essentially double the number of IP addresses on the network. The paper had a Class B IP scheme, with a Class C subnet mask, allowing for only 255 addresses per subnet. Because the IP phones are being put on a single subnet, DeWees upgraded to a Class A address scheme with a Class B subnet mask, giving the network more than enough addresses per subnet – more than 65,000 – to handle the IP phones.
The Times will use Dynamic Host Configuration Protocol to dynamically allocate IP addresses to the phones, as opposed to statically assigning numbers, which was done initially. “We had a few duplicate addresses, and the [IP PBX] really didn’t like that,” DeWees says.
Why did the Times go with Avaya for VoIP when it had a Cisco-centric data network? Dunkerley says they took a close look at Cisco’s AVVID (Architecture for Voice, Video and Integrated Data) IP telephony products and systems from Alcatel and Nortel, but it came down to Cisco and Avaya.
“The major reason we went with Avaya was because it was the incumbent technology” for voice, Dunkerley says. “That may sound like a cop-out, but there is value in that; the interfaces on the IP phones are exactly the same as on the old [Lucent] phones, and the management is the same as it was on the G3” PBX from Avaya.
That saves the cost of retraining 1,000-plus employees and the telecom staff. Incidentally, the newspaper plans on saving around 25 per cent per month on its US West and Verizon bills by consolidating T-1s to run data and voice to more than 30 remote offices and printing facilities.
Dunkerley says a deciding factor in choosing Avaya VoIP gear was “not so much about adding features,” as it was maintaining the features and familiarity of the old system. “You don’t want to lose anything or go backwards at all” when migrating to a new phone system, he says.
While competing systems offered new bells and whistles, each one seemed to take away features the newspaper could not do without. One example, Dunkerley says, was the ability for incoming, caller ID numbers to follow the call when transferred – a common PBX function.
“AVVID was designed by data engineers,” Dunkerley says, “while Avaya’s equipment was designed by telecom engineers.”