NCast N-Way Server - Manual (Page 20)

NCast N-Way Reference Manual
3.2.C
HANNEL
MTU S
ETTINGS
Packets transported through the multicast tunnel are limited to a size that is less than the MTU available for the
network link supporting the tunnel. If the media packet length is kept to the usual MTU size of 1500, packet
fragmentation will occur causing severe performance degradation.
The reduced packet length MTU must be set to 1476 or less for the Channel(s) used in an N-Way supported
session. A good policy is to reserve a set of Channels specifically for N-Way use. The MTU will then be correct
for the tunnel, and the other channels for other sessions will not need to utilize a non-standard MTU size.
Change the MTU fields as shown and update the Channel settings.
3.3.M
ULTICAST
S
ETTINGS
The multicast addresses entered into the address fields must be within the range of the multicast addresses
authorized for the N-Way account. If they are out of range, communication will be blocked in both directions by
the server.
The use of administratively-scoped multicast address ranges is a good policy for this service. The TTL setting
may be set low, but must be at least 1 or greater.
3.4.O
PERATING
R
ESTRICTIONS
There are some restrictions on use of Telepresenters with an N-Way Server:
•
Only one Telepresenter may be connected to an N-Way Server from a local LAN segment. Only one
multicast tunnel can originate or terminate on a LAN segment.
•
If a Telepresenter is on the same LAN segment as an N-Way Server, it need not use tunneling to join an
N-Way session, and the N-Way connection should be “Disabled”. The Telepresenter and Server will
NCast Corporation Revision 1.3
Page 20
MTU
changes