MVTX2801
Data Sheet
Network management (NM)
•
•
•
•
Global buffer reservation for NM and EF
Shaper for EF traffic
Option of strict priority scheduling
No dropping if admission controlled
and Expedited forwarding (EF)
Assured forwarding (AF)
•
•
Four AF classes
Programmable bandwidth partition, with option of
WFQ service
•
Option of delay-bounded service keeps delay
under fixed levels even if not
admission-controlled
•
•
Random early discard, with programmable levels
Global buffer reservation for each AF class
Best effort (BE)
•
•
Two BE classes
Service only when other queues are idle means
that QoS not adversely affected
•
•
Random early discard, with programmable levels
Traffic from flow control enabled ports
automatically classified as BE
Table 5 - MVTX2801 Features Enabling IETF Diffserv Standards
8.0 Port Trunking
8.1 Features and Restrictions
A port group (i.e. trunk) can include up to 4 physical ports, but all of the ports in a group must be in the same
MVTX2801.
The MVTX2801 provides several pre-assigned trunk group options, containing as many as 4 ports per group, or
alternatively, as many as 4 total groups.
Load distribution among the ports in a trunk for unicast is performed using hashing based on source MAC address
and destination MAC address. The other options include source MAC address only, destination MAC address only.
Load distribution for multicast is performed similarly.
If a VLAN includes any of the ports in a trunk group, all the ports in that trunk group should be in the same VLAN
member map.
The MVTX2801 also provides a safe fail-over mode for port trunking automatically. If one of the ports in the trunking
group goes down, the MVTX2801 will automatically redistribute the traffic over to the remaining ports in the trunk in
unmanaged mode. In managed mode, the software can perform similar tasks.
8.2 Unicast Packet Forwarding
The search engine finds the destination MCT entry, and if the status field says that the destination address found
belongs to a trunk, then the group number is retrieved instead of the port number. In addition, if the source address
belongs to a trunk, then the source port's trunk membership register is checked to determine if the address has
moved.
A hash key is used to determine the appropriate forwarding port, based on some combination of the source and
destination MAC addresses for the current packet.
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