Dial-On-Demand Routing (Ddr) Lists - Nokia IPSO 4.0 Reference Manual

2
9. Click Apply.
Note
Follow steps 8 through 21 in
the information for outgoing calls.
For more information about how to set up incoming numbers see
number".
10. Click Save to make your changes permanent.
For troubleshooting information, see

Dial-on-Demand Routing (DDR) Lists

As ISDN connections attract charges to establish and maintain connections, it is useful to have
only certain types of packets cause the connection to be set up. It is also useful to have timers
determine how long the connection should be maintained in the absence of these packets.
A Dial-on-Demand Routing (DDR) list is used to determine the packets that should bring up and
maintain an ISDN connection. This section explains how to configure DDR lists for ISDN
interfaces.
A DDR list is composed of one or more rules that are used to determine if a packet is interesting.
Interesting packets are those that establish and maintain a connection. Each rule has a set of
values used to match a packet and an action to take when a match occurs.
The following are the possible actions:
Accept—this is an interesting packet.
Ignore—this is not an interesting packet.
Skip—this rule is ignored.
When a packet matches a rule in the DDR list with an accept action, that packet is regarded as
interesting. An interesting packet causes the ISDN interface to set up a call by using the is
passed over the interface. The traffic passed could include traffic, which configured in the DDR
list, with an ignore action. If no packets that match an accept rule in the DDR list are transmitted
in the configured idle time, the connection is automatically disconnected. A DDR list is created
with a default rule that matches all packets. The associated action is accept. This action can be
set to skip so that all unmatched packets are deemed uninteresting.
Note
Setting a rule to skip effectively turns the rule off.
It is important to understand the difference between Access lists and DDR lists and how the two
interoperate. When a packet is sent over an interface, any Access list applied to that interface is
checked first. If the packet matches any rule in the Access list, the associated action is taken.
Therefore, if the packet matched a rule in the Access list that had an associated action of drop,
58
"To configure an ISDN logical interface to place calls"
"ISDN Troubleshooting."
Nokia Network Voyager for IPSO 4.0 Reference Guide
to set
"To add an incoming