11
• IP source address/destination address or subnets
• TCP/UDP source/destination port/port range
• IEEE 802.1p user priority bits
• Ingress physical source port
• IP Protocol ID (e.g., TCP, UDP, IGMP)
• EtherType (e.g., IP, IPX)
• IEEE 802.1Q VLAN ID
The BayStack 460 Switch also has the ability to read packets that have been marked from
other devices such as the Passport 8600 Switch. Additionally, weighted round robin prevents
normal priority traffic from being starved by expedited traffic (on a per-packet basis).
QoS and policy management
DiffServ QoS provides the ability to read, alter, prioritize, tag, or mark IP packets based
upon information embedded in the Type of Service (ToS) field. The level of service can be
marked in the embedded information inside the ToS field of each IP packet. DiffServ is
based on the ToS field. The BayStack 460 Switch has application-specific integrated
circuits (ASICs) to enable the DiffServ Code Point (DSCP) to be mapped to the IEEE
802.1p user priority bits to provide consistent QoS at Layer 3 (IP) and Layer 2 (Ethernet).
The QoS policies can be configured via the BayStack 460 Switch’s built-in Web-based
management tools to facilitate QoS or alternatively, Optivity Policy Services can be
utilized for dynamic end-to-end enterprise-wide policy and QoS management, facilitated
through the Common Open Policy Service (COPS) protocol.
Quality of Service provisioning
With Optivity Policy Services, policies can be created through a simple and intuitive drag-
and-drop workflow. Optivity Policy Services is the Policy Decision Point in a DiffServ
QoS implementation.
Further benefits include:
• Simple intuitive policy creation
• Ability to re-use common filter sets
• Provision of a network-wide view of policies currently in use
• Ability to avoid QoS provisioning errors
• Centrally managed DSCP and 802.1p queue mapping tables
• Saved time in provisioning the network—as thousands of CLI or Web transactions are
reduced to a few simple actions
Simplified QoS
The BayStack 460 Switch supports Nortel Networks Service Classes (NNSCs) which
provide simplified QoS provisioning. NNSCs provide factory-default QoS configurations,
eliminating the complexities often associated with QoS-enabled network deployments.
NNSCs provide default settings such as:
• DSCP marking per class
• DiffServ forwarding behavior (PHB) per class
• DSCP to queue mapping
• DSCP to 802.1p mapping
• Default scheduler per class
