Qos Classes; Table 56 Service Classes - Nortel business policy switch 2000 User Manual

290 Chapter 4 Policy-enabled networks

QoS classes

The BPS 2000 supports the following Nortel Networks QoS classes:
• Critical and Network classes have the highest priority over all other traffic.
• Premium class is an end-to-end service functioning similarly to a virtual
leased line. Traffic in this service class is normally guaranteed an agreed-upon
peak bandwidth. Traffic requiring this service should be shaped at the network
boundary in order to undergo a negligible delay and delay variance. This
service class is suitable for real-time applications like video and voice over IP.
The recommended PHB for this service is the Expedited Forwarding (EF)
PHB.
• Platinum, Gold, Silver, and Bronze classes use the Assured Forwarding (AF)
PHB. These classes are used for real-time, delay-tolerant traffic and
non-real-time, mission-critical traffic.
• Standard class is the best-effort IP service with an additional, optional use of
traffic classification that is used at the network boundary to request a better
effort treatment for packets that are in-profile (packets that do not break the
service agreements between the user and the service provider).
Table 56

Table 56 Service classes

Traffic category
Critical network control
Standard network control Network
Real time, delay
intolerant, fixed
bandwidth
Real time, delay tolerant,
low variable bandwidth
208700-C
describes the service classes and the required treatment.
Service class Application type
Critical Critical network control
traffic
Standard network control
traffic
Premium Interhuman
communications requiring
interaction (such as VoIP).
Platinum Interhuman
communications requiring
interaction with additional
minimal delay (such as
low-cost VoIP).
Required treatment
Highest priority over all other
traffic. Guaranteed minimum
bandwidth.
Priority over user traffic.
Guaranteed minimum
bandwidth.
Absolute bounded priority over
user traffic. No packet loss for
in-profile traffic. Virtual leased
line with lowest amount of
latency. Provisioned for peak
rate.
Higher-priority scheduling
providing guaranteed minimum
provisioned bandwidth.
Competes for additional
bandwidth.