34
FUR
THER
INFORMA
TION
APPENDIX B - Tips for success when networking ALIF units
ALIF units use multiple strategies to minimize the amount of data that they send
across networks. However, data overheads can be quite high, particularly when very
high resolution video is being transferred, so it is important to take steps to maximize
network efficiency and help minimize data output. The tips given in this section have been
proven to produce very beneficial results.
Summary of steps
• Choose the right kind of switch.
• Create an efficient network layout.
• Configure the switches and devices correctly.
Choosing the right switch
switches are what bind all of the hosts together in the subnet. However, they are
all not created equally, so choose carefully. In particular look for the following:
• 10Gigabit ports,
•
Support for
(or v3) snooping,
•
Support for
up to 9216-byte size,
• High bandwidth connections between switches, preferably Fiber Channel.
• Look for switches that perform their most onerous tasks (e.g.
) using
multiple dedicated processors (ASICS).
• Ensure the maximum number of concurrent ‘snoopable groups’ the switch can
handle meets or exceeds the number of ALIF transmitters that will be used to create
multicast groups.
• Check the throughput of the switch: Full duplex, 10Gbps up- and down- stream speeds
per port.
• Use the same switch make and model throughout a single subnet.
• You also need a
switch. Ensure that it can operate efficiently as an
Creating an efficient network layout
Network layout is vital. The use of
also introduces certain constraints, so
take heed:
• Keep it flat. Use a basic line-cascade structure rather than a pyramid or tree
arrangement.
• Keep the distances between the switches as short as possible.
• Ensure sufficient bandwidth between switches to eliminate bottlenecks.
• Where the AIM server is used to administer multiple ALIF transceivers, ensure the AIM
server and all ALIF units reside in the same subnet.
• Do not use VGA to display port converters, instead replace VGA video cards in older
systems with suitable display port replacements. Converters cause ALIF TX units to
massively increase data output.
• Wherever possible, create a private network.
The recommended layout
The layout shown below has been found to provide the most efficient network layout for
rapid throughput when using IGMP snooping:
• Use no more than two cascade levels.
• Ensure high bandwidth between the two L2 switches and very high bandwidth between
the top L2 and the L3. Typically 10GB and 20GB, respectively for 48 port L2 switches.
continued