L-IP User Manual
94
LOYTEC
Version 6.1
LOYTEC electronics GmbH
The L-IP with IP address 192.168.1.100 is member of IP Channel 1 and can be accessed
through the Internet. The L-IP devices with IP addresses 192.168.101 to 192.168.1.110
form another logical IP Channel 2 that communicates with the devices on the IP Channel 1
over the TP-1250 channel, which is used in high-speed backbone mode for optimum
networking performance. Note that devices on both IP Channels 1 and 2 can of course
connect to the same physical network wiring. Furthermore both IP Channels 1 and 2 must
have a separate configuration server that manages the L-IP devices on the different
channels. In the example in Figure 88 the L-IP with address 192.168.1.100 acts as the
configuration server for IP Channel 1 and the L-IP with IP address 192.168.1.101 acts as
the configuration server for IP Channel 2.
7.4 Multi-Cast Configuration
IP multi-casting is a feature of the IP protocol that allows one packet to be delivered to a
group of IP hosts. To receive such multi-cast packets, each IP host must be member of a
multi-cast group. This group is identified by a multi-cast address (e.g. 225.0.0.37) and a
UDP port number.
The L-IP supports both unicast and multi-cast delivery of CNIP data packets. Using multi-
cast is recommended when using L-IPs in the Smart Switch Mode. For those L-IPs
configure a multi-cast address in the IP configuration menu. Please contact your system
administrator to obtain a valid multi-cast address for your network. All L-IPs must be
configured with the same multi-cast address and use the same client port (1628 is
recommended). Also note, that multi-cast addresses cannot be routed on the Internet. They
can only be used in a LAN or VPN environment.
If you configure multi-cast there may be some devices, which do not support this feature. In
this case, the L-IP uses a hybrid scheme and sends unicast to those devices, which are not
configured for multi-cast. Note, that the L-IP determines automatically, when to switch to
the multi-cast mode depending what types of devices are in the channel and on the traffic
burden for those devices. As a rule of thumb multi-cast is used when there are only
switches/repeaters in the channel and it is not used when there are only configured routers.
To detect, if the L-IP utilizes the multi-cast feature to send to other devices, contact the
Extended CEA-852 device statistics in the statistics menu (Section 6.3). The entry “Channel
Routing Mode” reads SL (send list) if packets are routed to the multi-cast group. It reads
CR (channel routing) if the normal unicast method is employed. Also the entry “Multi-cast
packets sent” in the CEA-852 device statistics menu (Section 6.3) counts the number of
multicast packets transmitted to the group. If this item remains zero, no multi-cast is used by
the L-IP.
7.5 Internet Timing Aspects
If the L-IP is used over the Internet or in a large Intranet with unpredictable network delays,
the user should become familiar with the following advanced timing aspects. Channel
Timeout is set in the configuration server whereas escrowing and aggregation are set in the
CEA-852 client device. The Channel Delay is a channel property of LNS and can be set in
NL220, LonMaker or other network management tools.
Table 8 summarizes the timing values that must be set when operating the device under
WAN conditions.