Rabu, 2 April 2008
VoIP systems vary in so many ways that businesses need to comb through the gory details of what vendors offer to make sure they get the features and functions they need, attendees were told at VoiceCon Orlando 2008.
Potential customers were urged to consider factors they might tend to overlook, including whether systems can be made resilient to failures, how many devices are needed to build the system, whether they are energy efficient, whether phones offer all the features customers want, and how well they support cell phones as PBX extensions.
These tips came out during a panel discussion of bids that were presented by a group of vendors on a hypothetical RFP put together by Allan Sulkin, president of TEQConsultant Group, who led a tutorial on the subject. (Compare IP PBXes.)
There are some basics such as redundancy of the IP PBX that businesses must seek, Sulkin said. "If you don't get dial tone, nothing counts," he said. The good news about such redundancy is that it's more affordable than it used to be. "It is a fraction of the cost it was 10 years ago," he said.
Businesses also should make sure phone service in a branch office will survive by failing over to another site if primary call-control gear or WAN links go down. Customers have to pay a lot for this type of bullet-proofing, Sulkin said, but it's worth it. "They're not going to save you money; in fact these systems cost you more money," he said. But not being able to continue business if a site fails is even more costly. The U.S. Department of Homeland security requires failover sites that can continue business in the case of disasters, he added.
Sulkin also recommended looking for consolidated functionality on VoIP servers. Some vendors put multiple functions on a single server, which saves on electricity when compared with vendors that split applications among multiple servers. The more servers, the more maintenance and the more energy used, Sulkin said. Gear is trending toward being more energy efficient, Sulkin said, so when buying, consider power consumption.
Certain network infrastructure also can help energy savings, the panel noted. Some Power-over-Ethernet switches, for instance, can shut down power to phones and wireless access points during off hours when nobody is at work to use them.
If tying cell phones into the PBX is important, look carefully at how this is done.
Third-party suppliers are needed in some cases to make cell phones extensions of the IP PBX, introducing one more vendor to the management and maintenance mix. In other cases, vendors support cell phones as PBX extensions but only for incoming calls, unless special client software is installed on them.
Businesses hoping to use VoIP as part of a unified communications (UC) deployment should shop carefully. Integration with popular Microsoft and IBM UC platforms is still on the road map for some vendors.
Some UC use requires customizing UC clients, which may fall to the user, Sulkin said. "You become your own UC programmer and IT department," he said.
Even handsets vary. (Compare IP phones.) Some vendors could not supply all the features sought in the RFP. Some could not provide whisper paging, which lets operators signal that another call is coming to a busy phone with a message saying who it is and what is wanted. Others could not provide a phone supporting Bluetooth for headsets or color displays.
One vendor, Mitel, even has phones that act as wireless access points for mobile handsets, a feature that can allow a gradual shift to wireless LANs if budgets are tight.
Lastly, businesses should check out how 911 calls are handled, Sulkin said. Vendors vary on whether and how they support information about the physical location of phones making 911 calls. Some vendors' gear automatically updates the information, but the data must be manually transferred to sites handling emergency calls.