Support For Pre-802.3Af Standard Powered Devices; Appendix D: Pim Sparse Mode - HP 5400zl Series Technical Overview

Support for pre-802.3af standard powered devices

The HP ProCurve Switch 5400zl and 3500yl series also support a number of pre-802.3af standard
powered devices. These include:
• Cisco 7902G, 7905G, 7912G, 7940G, 7960G IP Phones
• Cisco Aironet 350, 1100, 1200, 1230AG Access Points
The Cisco pre-802.3af standard IP phones require the use of a straight-through cable for connectivity
to the PSE. These IP phones are dependent on the polarity of the DC voltage (a violation of the IEEE
802.3af standard) and will not work properly if the Data Pairs (wires 1 and 2, and 3 and 6) are crossed
over anywhere in the cable plant between the IP phone and power sourcing equipment.

Appendix D: PIM Sparse Mode

In Protocol Independent Multicast-Sparse Mode (PIM-SM), the assumption is that there are no hosts
that want the multicast traffic unless they specifically ask for it. In contrast, PIM Dense Mode (PIM-
DM) assumes downstream router membership unless it receives an explicit prune message. PIM-SM is
appropriate for wide-scale deployment for both densely and sparsely populated groups and is the
optimal choice for all production networks regardless of size and membership density.
The operation of PIM-SM centers on the use of a shared tree, with a router functioning as a rendezvous
point (RP), the root of the tree. A shared tree prevents each router from maintaining source and group
state information for every multicast source. Regardless of the number or location of multicast
receivers, multicast senders register with the RP and send a single copy of multicast data through it to
the registered receivers. Also, regardless of the location or number of sources, group members register
to receive data and always receive it through the RP.
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