7 Ways To Improve VoIP Call Quality

February 23, 2007 by Garrett Smith

VoIP Call Quality is the Most Important Factor For Today’s VoIP Consumer

Tracy Mayor over at VoIP-News have an excellent post on seven ways to improve VoIP call quality. Here are Tracy’s top 7 ways to improve VoIP call quality:

1. Go private rather than public. “The public Internet is always going to be more subject to disruption and therefore to quality issues than private networks,” points out Jan Dawson, vice president of US Enterprise Practice at Ovum, a Boston-based telecom consultancy. “The best VoIP services use private, dedicated networks rather than the public Internet.”

2. Better cables equal better performance. For many companies, only CAT-5 cabling on-premises is robust enough and fast enough to handle VoIP traffic adequately.

3. Hash things out with your vendor ahead of time. “The most important question to ask is how will you care for your VoIP infrastructure on Day 2,” the day after installation, says Pierce. “Most customers don’t think about per-call monitoring, call management or trouble-resolution until later, and they get themselves into deep trouble that way.” To avoid the same mistake talk to your vendor . Ask your vendor what, if any, call- and network-monitoring tools they include or at least support. With service providers work up service-level agreements (SLAs) that specify what quality-control metrics will be used to measure jitter and packet loss and how such problems will be addressed.

4. Allocate bandwidth wisely. Separate is better, says Dawson, meaning companies should consider using either two separate LANs for voice and data or keeping traffic virtually separate through use of a VLAN. Full duplex, non-blocking switches will help to avoid collision and packet loss. Further, make use of network analysis tools to identify and eliminate congestion points on the network.

5. Buy VoIP hardware, handsets and the IP PBX, with built-in echo cancellation. The longer the echo cancellation “tail length” (measured in milliseconds), the more effectively the technology will work.

6. Upgrade your existing network management and monitoring suite. They should accommodate VoIP, which includes upgrading your RMON (remote network monitoring) probe and protocol analyzers to recognize and decode VoIP traffic.

7. …Or bring a network monitoring system online for the first time. The ultimate goal should be a system that’s capable of proactively monitoring each call from SIP phone to SIP phone across the WAN, says Pierce. While she warns “there’s no one single off-the-shelf package” that can answer all your VOIP monitoring needs, good places to start are with network monitoring suites from your IP PBX vendor or VoIP-accommodating network-monitoring suites like those from HP, Fluke/Visual Networks, Psytechnics and IBM’s Tivoli division, which now owns the Netcool product line formerly sold by Micromuse.

I would like to add few other ways that you can improve your VoIP call quality:

  1. Don’t Oversubscribe. Most businesses try to make too many calls over to small of a pipe. Bad idea. Make sure you have adequete bandwidth available for the amount of calls you need to make.
  2. Upgrade your network infrastructure. Surprisingly, the cost of upgrading your network infrastructure is cheaper than ever. For example, 24 port PoE switches can now be had for around $399. If your network is not in tip-top shape, you run the risk of having packet loss.
  3. Experiment with Codec Size.If you have enough bandwidth, try using a large codec. Although your service provider might compress this on their network, it should not affect the decompression of the codec on the LAN. Alternatively, you could pick a service provider that uses a larger codec by default.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.