Appendix A - Tips For Success When Networking Alif Units - ADDER AdderLink Infinity Manager User Manual

Appendix A
Tips for success when networking ALIF units
ALIF units use multiple strategies to minimise 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
maximise network efficiency and help minimise 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
Layer 2 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:
• Gigabit (1000Mbps) or faster Ethernet ports,
• Support for IGMP v2 (or v3) snooping,
• Support for Jumbo frames up to 9216-byte size,
• High bandwidth connections between switches, preferably Fibre Channel.
• Look for switches that perform their most onerous tasks (e.g.
snooping) 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, 1Gbps up- and down-
stream speeds per port.
• Use the same switch make and model throughout a single subnet.
• You also need a Layer 3 switch. Ensure that it can operate efficiently as an
IGMP Querier.
Layer 2 (and 3) switches known to work
• Cisco 2960 • Extreme Networks X480
• Cisco 3750
• HP Procurve 2810
• Cisco 4500
• HP Procurve 2910
• Cisco 6500 • H3C 5120
For the latest list of switches known to work with ALIF and
setup instructions for them, please go to
IGMP
• HuaWei Quidway
s5328c-EI
(Layer 3 switch)
www.adder.com
Creating an efficient network layout
IGMP snooping
Network layout is vital. The use of
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 DVI converters, instead replace VGA video cards in older
systems with suitable DVI replacements. Converters cause ALIF TX units to
massively increase data output.
• Stackable switches will allow you to create more ports at each cascade level.
• 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:
ALIF RX
Layer 3
Switch
(Querier)
ALIF RX
ALIF RX
Layer 2 Switch
ALIF RX
ALIF RX
Layer 2 Switch
ALIF TX
• 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.
also introduces certain
ALIF TX
ALIF RX
20GB link
ALIF TX
ALIF RX
10GB link
ALIF RX
ALIF RX
1GB links
continued
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