By Yuval Shavit, Features Writer
Voice over IP (VoIP) can integrate voice with other forms of communication and save clients money on long-distance charges, but there's more to deploying on-premise VoIP than just putting new phones on desks. In this installment of our series on VoIP services, we explore VoIP implementation best practices for systems integrators (SIs) offering these services to their clients.
With the typical on-premise VoIP implementation, voice data travels over the client's existing LAN. As with any other data, network congestion can delay packets or even cause some to be dropped. While this is just a minor inconvenience for most forms of data -- an Intranet page taking slightly longer to load, for instance -- even a few dropped VoIP packets can introduce unacceptable echoes or breaks in a voice stream.
Customers are used to the nearly flawless voice quality they get with standard phone lines and will not settle for lower quality with VoIP services, according to several systems integrators (SIs). To support VoIP, networks have to be assessed and often upgraded as a first step -- in fact, many vendors require it.
This can be a great revenue generator and gives you a chance to up-sell or cross-sell services. If
your client is considering an upgrade to Gigabit or 10 Gigabit Ethernet, the increased load from a
VoIP system provides an incentive to do so. A faster infrastructure is also important for getting
the most out of a modern wireless LAN (WLAN), which in turn can open the door for a voice over WLAN
Larger companies tend to have robust networks that are mostly ready to handle VoIP implementation, but networks at small and medium-sized businesses (SMBs) often need significant upgrading, especially when it comes to the connection between sites, according to Doug Tassan, vice president of service delivery at Paranet Solutions LLC, an SI in Plano, Texas.
The most expensive upgrade at these companies is usually the hub, said Steve Vicinanza, founder and CEO of BlueWave Computing Inc., a Smyrna, Ga.-based SI. Vicinanza said he often recommends a hub capable of Power over Ethernet (PoE), which will allow you to power phones without having to run a separate electricity line to them. You should figure about 60 to 100 Kbps per conversation, he said.
But because VoIP services need to be available 24/7 -- even during peak traffic hours -- just setting up enough bandwidth to handle average loads is not enough. You should prioritize your client's network to make sure that VoIP data travels freely all the time, and you may want to set up a virtual LAN (VLAN) for the VoIP devices to guarantee they get all the bandwidth they need.
You or your client should also consider negotiating with the Internet service provider (ISP) to ensure that VoIP packets are prioritized across the network, so that quality of service (QoS) is guaranteed even after data packets leave the LAN, Vicinanza said.
Aside from bandwidth concerns, setting up a VLAN will also make security easier to manage. Because VoIP implementations combine phone service and data networks, you need to worry about security for both worlds, SIs said. Denial-of-service (DoS) attacks can take down a VoIP line or hackers can try to get free long-distance, as they have been doing for years with traditional PBXs.
Your approach to security with VoIP should be similar to any other data, SIs said: Know the devices, read up on their security issues, and make sure you have the latest patches. If you're using VoIP services between different sites, make sure that all data is encrypted through a VPN, so outside parties can't listen in on the line.
Once the pre-assessment is done and it's time to start the VoIP implementation, most SIs roll out the system by geography, starting with one remote branch or workgroup, said Henry Dewing, principal analyst at Forrester Research Inc. This can help you iron out any complications and boost your customer's confidence in the technology.
Deploying the system at just one site also lets you avoid the additional challenges in getting good voice quality across your client's WAN. Because VoIP is completely separate from traditional phone lines, you can set up the system without interrupting normal phone service and then switch over quickly.
Although some routers can work in a VoIP-TDM hybrid mode, supporting both phone systems, most SIs said they don't use that feature -- when an office or group is switched, it goes to full VoIP. But having the hybrid option lets you keep a few TDM lines for failover and 9-1-1 emergencies in case the VoIP implementation fails for any reason, Tassan said.
This was first published in November 2007