Motorola V186 - Cell Phone - GSM System Planner Manual page 107

Communications
IP Conversion Table Enhancements
An IP conversion table can be assigned to each RTU/FEP. It maps each site ID+link ID
(port) to an IP address. The link ID column supports multiple MDLC over IP ports per
RTU. Each link ID uniquely identifies the port/IP connection of that RTU. The table
enables the MDLC over IP port to transmit MDLC packet to its destination based upon
its site ID and link ID (port).
The enhanced IP conversion table also supports the user of a host name instead of a
numeric IPv4 address (IP address). In order to use host names, the operator must support
this in the network DNS Server, and the user must specify them in the appropriate port
configuration. The IP conversion table is dynamic, which means its numeric addresses
are automatically learned/updated in runtime, for example when a new RTU is added, or
an existing one changes its addresses. In some cases, such as dynamic addresses of
RTUs, there is no need to download that table to FEP, simply because RTUs addresses
are updated when they transmit to the FEP. In this case, it is recommended that the user
application perform these transmissions periodically. Note: The IP conversion table
learns only numeric IP addresses. Host names of other RTUs are not learned.
Using Host Names
Sometime it is necessary to refer to an RTU or FEP using a host name rather than a
numeric IP addresses. Any MDLC over IP port (Ethernet or RS232/PPP) has that option,
however it is the responsibility of the user and network to make sure this is supported.
In the IP conversion table, it is possible to set a host name instead of a numeric IP address
for a specific site + link ID. The link ID, for example LINE5, identifies the port/IP
connection of that site.
To enable this, the port needs the list of DNS servers for that MDLC over IP port. DNS
list can be automatically learned. The list must be set only for an Ethernet port configured
as Static IP address mode. An Ethernet port configured as DHCP or an RS232 port
configured as PPP automatically learns this list from the network, and the user does not
need to set them.
Note: Some PPP connected radios such as TETRA and ASTRO IV&D radios do not
provide DNS information. These systems usually do not use host names either, but if
necessary, the user can set the list of DNS Servers in the port configuration.
The FQDN option for an Ethernet port configured as DHCP updates the DNS servers
when a new IP address is allocated to it by DHCP. The user need only set the full host
name of that port. A warning is logged if the router/DHCP server does not support this
option.
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