R0106-HP MSR Router Series Layer 2 - WAN Configuration Guide(V7)

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When you configure a synchronous/asynchronous serial interface, follow these guidelines:
• If the connected modem is asynchronous:
{ Configure the interface to operate as an asynchronous interface (by using the physical-mode
async command) and to operate in protocol mode (by using the async-mode protocol
command).
{ Configure the call-in/call-out rights for the modem on the corresponding user line for the
interface.
• If the connected modem is synchronous, configure the interface to operate as a synchronous serial
interface (by using the physical-mode sync command).
For more information about modem management, see "Managing a modem."
Configuring link layer/network/routing protocols on the dialup
interface
Dialup interfaces support PPP, IP, RIP, and OSPF. For information about configuring these protocols, see
"Configuring PPP and MP," Layer 3—IP Services Configuration Guide, and Layer 3—IP Routing
Configuration Guide.
When you configure PPP, follow these guidelines:
• For traditional DDR, configure PPP commands on the same interface as DDR parameters.
• For bundle DDR:
{ On the calling side, perform the following tasks:
− Configure PPP commands on dialer interfaces.
− Configure the same PPP commands on physical interfaces to guarantee successful PPP link
parameters negotiation.
{ On the called side, configure PPP commands on physical interfaces.
Associating a dial rule with a dialup interface
A dial rule determines when a dialup interface initiates DDR calls. You need to configure dial rules only
on the initiator of DDR calls.
You can configure a dial rule to match only IP packets or use an ACL to match packets.
Permitted protocol packets or packets that match a permit statement of an ACL are interesting packets.
When receiving an interesting packet, DDR performs one of the following tasks:
• Sends it out if a link is present and resets the idle-timeout timer.
• Originates a new call to set up a link if no link is present.
Denied protocol packets or packets that match a deny statement of an ACL are uninteresting packets.
When receiving an uninteresting packet, DDR performs one of the following tasks:
• Sends it out without resetting the idle-timeout timer if a link is present.
• Drops it if no link is present.
For DDR to forward packets correctly, configure a dial rule and associate it with the dialup interface.
To associate a dial rule with a dialup interface: