Operation Manual

Basic Design of ISDN-WANs and Configuration Overview 77
OSPF is a link state protocol implementation. OSPF exchanges
routing information only when network changes occur. OSPF further
uses OSPF Hello packets to reassure the remote side of the link is
available. The following mechanism is implemented to reduce traffic
produced by this routing protocol:
- OSPF Hello Timer
The OSPF Hello Timer defines the frequency of OSPF Hello
packets. This timer can be set per interface. You can - and over
ISDN you must - change the default of 10 seconds to a higher
value if you decide to use OSPF instead of static routes. The
maximum value is approximatly 18 hours.
Recommendation
For TCP/IP over ISDN, the general recommendation is to use static
routes. If you want to use a routing protocol instead, use of OSPF is
recommended.
♦♦ AppleTalk - RTMP
For AppleTalk, the routing protocol RTMP is supported.
RTMP consistently exchanges routing information, i.e. updates
routing tables in a periodic manner. This is done per default every 10
seconds, whether changes appear or. The following mechanism is
implemented to reduce traffic produced by this routing protocol.
- RTMP Routing Update Timer
With RTMP Routing Update Timer you can - and over ISDN you
must - change the default of 10 seconds for exchange of routing
information to a higher value, best to the max. value of 30
minutes.
Recommendation
For AppleTalk over ISDN, the general recommendation is to use
static routes. If you want to use RTMP be aware that routing infor-
mation is at least exchanged every 30 minutes.
If you choose a routing protocol instead of static routes/services you
can set up classic WAN links, of course. You can also use ISDN
Classic and Dynamic ISDN Interface Usage with Routing Protocols
configuration overview.pm6 28.05.97, 00:0377