Design Reference
Table Of Contents
- Contents
- Chapter 1: Introduction
- Chapter 2: New in this release
- Chapter 3: Network design fundamentals
- Chapter 4: Hardware fundamentals and guidelines
- Chapter 5: Optical routing design
- Chapter 6: Platform redundancy
- Chapter 7: Link redundancy
- Chapter 8: Layer 2 loop prevention
- Chapter 9: Spanning tree
- Chapter 10: Layer 3 network design
- Chapter 11: SPBM design guidelines
- Chapter 12: IP multicast network design
- Multicast and VRF-lite
- Multicast and MultiLink Trunking considerations
- Multicast scalability design rules
- IP multicast address range restrictions
- Multicast MAC address mapping considerations
- Dynamic multicast configuration changes
- IGMPv3 backward compatibility
- IGMP Layer 2 Querier
- TTL in IP multicast packets
- Multicast MAC filtering
- Guidelines for multicast access policies
- Multicast for multimedia
- Chapter 13: System and network stability and security
- Chapter 14: QoS design guidelines
- Chapter 15: Layer 1, 2, and 3 design examples
- Chapter 16: Software scaling capabilities
- Chapter 17: Supported standards, RFCs, and MIBs
- Glossary
Traffic category Application example ASC
Real-Time, Delay Intolerant IP telephony; interhuman
communication
Premium
Real-Time, Delay Tolerant Video conferencing; interhuman
communication.
Platinum
Audio and video on demand;
human-host communication
Gold
NonReal-Time
Mission Critical
Interactive eBusiness (B2B, B2C)
transaction processing
Silver
NonInteractive Email; store and forward Bronze
NonReal Time, NonMission Critical FTP; best effort Standard
PointCast; Background/standby Custom/ best
effort
QoS and filters
Filters help you provide QoS by permitting or dropping traffic based on the parameters you
configure. You can use filters to mark packets for specific treatment.
Typically, filters act as firewalls or are used for Layer 3 redirection. In more advanced cases,
traffic filters can identify Layer 3 and Layer 4 traffic streams. The filters cause the streams to
be re-marked and classified to attain a specific QoS level at both Layer 2 (802.1p) and Layer
3 (DSCP).
Traffic filtering is a key QoS feature. Virtual Services Platform 4000, by default, determines
incoming packet 802.1p or DiffServ markings, and forwards traffic based on their assigned
QoS levels. However, situations exist where the markings are incorrect, or the originating user
application does not have 802.1p or DiffServ marking capabilities. Also, you can give a higher
priority to select users (executive class). In these situations, use filters to prioritize specific
traffic streams.
You can use filters to assign QoS levels to devices and applications. To help you decide
whether or not to use a filter, key questions include:
1. Does the user or application have the ability to mark QoS information on data
packets?
2. Is the traffic source trusted? Are the QoS levels configured appropriately for each
data source?
Users can maliciously configure QoS levels on their devices to take advantage of
higher priority levels.
3. Do you want to prioritize traffic streams?
This decision-making process is outlined in the following figure.
QoS design guidelines
130 Network Design Reference for Avaya VSP 4000 February 2014
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