SMC Networks SMC6924VF manual Class-of-Service CoS Support

ADVANCED TOPICS

Based on the group membership information learned from IGMP, a router/switch can determine which (if any) multicast traffic needs to be forwarded to each of its ports. At Layer 3, multicast routers use this information, along with a multicast routing protocol such as DVMRP, to support IP multicasting across the Internet.

Note that IGMP neither alters nor routes any IP multicast packets. A multicast router/switch must be used to deliver IP multicast packets across different subnetworks.

Class-of-Service (CoS) Support

The TigerSwitch 100 provides two transmit queues on each port, with a weighted round-robin scheme. This function can be used to provide independent priorities for various types of data such as real-time video or voice, and best-effort data.

Priority assignment to a packet in the TigerSwitch 100 can be accomplished in any of the following ways:

•Priority can be explicitly assigned by end stations which have applications that require a higher priority than best-effort. This switch utilizes the IEEE 802.1p and 802.1Q tag structure to decide priority assignments for the received packets.

•A port may be manually configured as high priority. In this case, when any other port receives traffic from a high-priority port, that traffic is automatically placed in the high-priority output queue.

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