Switching to VoIP

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Chapter 9: Quality of Service

MPLS has the following general characteristics:

• Is usually managed with switches

• Can run transparently within other labeled switching solutions such as ATM

• Is intended for carrier-grade networks

• Mimics ATM in function, but can be used across a variety of non-ATM net-

works, such as TCP/IP

• Is the most flexible, and the most sophisticated, QoS mechanism for VoIP

systems

Residential QoS

Providing reliable voice quality using VoIP in the home or small office is a challenge

for several reasons. First, residential broadband connections aren’t always operated

by the same people operating the VoIP service; this limits the ability of VoIP imple-

menters to troubleshoot and support network-related problems. Second, most

broadband Internet connections aren’t supported by a backbone that has QoS mea-

sures. While it is common for many ISPs to prioritize in the style of 802.1p, almost

none of them guarantee a service level. Finally, residential broadband routers haven’t

historically supported any QoS measures internally, though this is changing.

There aren’t solutions to the shortcomings of the ISP’s networks, but installing a

QoS measure in the home is a good step to take. As with enterprise networks, the

QoS enforcement points are routers. Some residential ...