Managing limited or pilot IP Telephony deployments isn't a big challenge and troubleshooting isn't necessarily an issue. But at scale, management, monitoring and troubleshooting VoIP is a major task. Network managers have to ensure that the network (especially the Wide Area portion) maintains the quality of service required to deliver voice acceptably; and they have to be able to quickly ascertain what's gone wrong when voice quality is sub-par. Understand how to engineer a WAN for VoIP and the elements you need in a network management infrastructure that ensures efficient management and troubleshooting.

1. Managing and Troubleshooting
VoIP
Sung Moon
Director of Technology
Avaya Global Services

2. Topics
• Design and Implementation
• Monitoring
• Troubleshooting

3. Decide With Your Service
Provider…
• What goes in?
• How does it get treated?
• What comes out?

4. What Goes In?

5. What Goes In? VoIP Audio
• How will this traffic be classified?
• Recommend marking at L3 (IP Header) using
DSCP for end to end integrity of marking.
– L2 tagging is not preferred because it must be
converted to L3 and back to L2 at various points.
• Expedited Forwarding PHB (RFC 3246) is the
industry standard.
• Simply put, mark your audio with DSCP 46,
and coordinate w/ your SP.