OPTICAL SYSTEMS DESIGN
DOC ID: 10118101
OSD2512 OPERATOR MANUAL
PAGE 169
POLICIES
Network Policy Discovery enables the efficient discovery and diagnosis of
mismatch issues with the VLAN configuration, along with the associated
Layer 2 and Layer 3 attributes, which apply for a set of specific protocol
applications on that port. Improper network policy configurations are a very
significant issue in VoIP environments that frequently result in voice quality
degradation or loss of service.
Policies
are only intended for use with applications that have specific 'real-
time' network policy requirements, such as interactive voice and/or video
services.
The network policy attributes advertised are:
1. Layer 2 VLAN ID (IEEE 802.1Q-2003)
2. Layer 2 priority value (IEEE 802.1D-2004)
3. Layer 3 Diffserv code point (DSCP) value (IETF RFC 2474)
This network policy is potentially advertised and associated with multiple sets
of application types supported on a given port. The application types
specifically addressed are:
1. Voice
2. Guest Voice
3. Softphone Voice
4. Video Conferencing
5. Streaming Video
6. Control / Signalling (conditionally support a separate network policy for the
media types above)
A large network may support multiple VoIP policies across the entire
organization, and different policies per application type. LLDP-MED allows
multiple policies to be advertised per port, each corresponding to a different
application type. Different ports on the same Network Connectivity Device
may advertise different sets of policies, based on the authenticated user
identity or port configuration.
It should be noted that LLDP-MED is not intended to run on links other than
between Network Connectivity Devices and Endpoints, and therefore does not
need to advertise the multitude of network policies that frequently run on an
aggregated link interior to the LAN.
