zl50416 Zarlink Semiconductor, zl50416 Datasheet - Page 36

• Manufacturer Part Number: zl50416
• Description: Managed 16-port 10/100 M + 2-port 1 G Ethernet Switch
• Manufacturer: Zarlink Semiconductor

Features of the ZL50416 that correspond to the requirements of their associated IETF classes are summarized in
the table below.
8.0
8.1
A port group (i.e. trunk) can include up to 4 physical ports, but when using stack all of the ports in a group must be
in the same ZL50416.
There are two trunk groups.
Load distribution among the ports in a trunk for unicast is performed using hashing based on source MAC address
and destination MAC address. Three other options include source MAC address only, destination MAC address
only, and source port (in bidirectional ring mode 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 ZL50416 also provides a safe fail-over mode for port trunking automatically. If one of the ports in the trunking
group goes down, the ZL50416 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
The search engine finds the destination MCT entry, and if the status field says that the destination port 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.
A hash key, based on some combination of the source and destination MAC addresses for the current packet,
selects the appropriate forwarding port, as specified in the Trunk_Hash registers.
Features and Restrictions
Unicast Packet Forwarding
Port Trunking
Network management (NM) and
Expedited forwarding (EF)
Assured forwarding (AF)
Best effort (BE)
Table 11 - ZL50416 Features Enabling IETF Diffserv Standards
Zarlink Semiconductor Inc.
ZL50416
Global buffer reservation for NM and EF
Option of strict priority scheduling
No dropping if admission controlled
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
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
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Data Sheet