VoIP troubleshooting can be a daunting task for even the most seasoned professional but we’re here to take the pain away! Let us help you design and implement the perfect VoIP network with assurance of good QOS (quality of service) throughout.

Here are the items we typically review for the best VoIP voice quality:

• Turn off SIP ALG or SIP Helper in your firewall
• Test main ISP connection with a VoIP Connection Test
• Setup VLAN for IP phones, use DHCP options to move VoIP phones to the correct VLAN
• Implement dedicated voice ISP connection if primary isn’t suitable to share voice/data
• Check VoIP packets using tools like Wireshark, compare LAN side to WAN side
• Test network cabling with Fluke cable certifiers if issues are contained to 1 or 2 particular phones
• Inspect SIP SDP details if one-way audio occurs
• Install an VoIP monitoring appliance on-site if intermittent issues persist

Are you wondering if the DSCP and TOS QOS settings you’ve been told about will improve the VoIP experience on your local network? The short answer is: No.

Did you know: The real-world truth is that most local area networks (LANs) run at gigabit speeds which is 1,000,000 Kbps. A VoIP phone call only consumes 100 Kbps and therefore the average corporate LAN is capable of running 10,000 concurrent phone calls! To be fair, it is possible to end up with some network link bottlenecks in a large environment. (ie. a campus with multiple buildings or wireless backbones) These bottlenecks could hinder VoIP unless the QOS settings give it priority, but this represents a very small subset of business networks.

Your ISP upload speed is typically the weakest link in your VoIP chain. Another common source of problems is an ISP service that delivers packets at an inconsistent rate – even through internet browsing may seem fine. Wireless internet providers are especially prone to this type of degradation and Coax delivered internet can also cause inconsistent results in cases where their cable is affected by weather.

Contact Atcom if you’d like professional assistance designing or troubleshooting your VoIP network.