Application Guide: detailed analysis of ISDN Router configurations

The configuration of the ISDN Router is very similar to that of the general router. Next we will explain the configuration of the ISDN Router in several steps. Use The debug dialer event and debug dialer packet commands to enable The corresponding debug switch of DDR. If you can see "DCC: The interface has no dialer-group. "or" DCC: it is an uninteresting packet "prompt information.

Use the display current-configuration command to view the configuration of the dial-up port. If the dialer-group command is not configured on the dial-up port, add the ISDN Router configuration; if dialer-group has been configured for the ISDN Router, check whether the sequence number of dialer-group is consistent with that of dialer-rule, and whether the trigger message type or condition set by dialer-rule is correct. Remember that dialer-rule is disabled by default unless it is configured as permit ). The correct dialing is possible only when "DCC: it is an interesting packet" is displayed.

Dialing string Not Configured

Run the debug dialer event and debug dialer packet commands to enable the debug switch for DDR. If "DCC: there is not a dialer route matching this address" and "DCC: there is not a dialer number on the interface, failed, discard packet "debugging information, use the display current-configuartion command to view the dialing port configuration. If neither the dialer route command nor the dialer number command is configured on the outbound call interface, the dialer number must be configured on the ISDN Router for shared DCC; one of them is used for Round Robin DDR configuration ). For the called interface, the dialing string must be configured for Synchronous dialing port; for other interfaces, this configuration can be omitted.

Dialing string setting error

The main caller has initiated a call. Use the debug dialer packet, debug dialer event, debug modem at, and debug isdn q931 commands to enable the corresponding debug switch, if no call information prompt is received on the called end, first check whether the physical connection of the called end is correct. If the connection is correct, you need to check whether the relay number, BRI number, or telephone number of the called end are consistent with the dial-up string configured on the main call end.

The call chain creation process failed.

The main caller has initiated a call. After the debug dialer packet and debug dialer event commands are used to enable the DDR debugging switch, if the prompt message is normal, and the debug ppp packet command is used if the physical interface is encapsulated as PPP) no PPP message output, and the message "DCC: wait-for-carrier-timeout on a link on interface ***, shutdown! Start enable-time, and then call to stop. Perform the following analysis: if Modem dialing is used, use the debug modem at and debug modem event commands to enable the Modem debugging switch. If the line is busy, you must set the call number yourself. If the message "DCC: wait-for-carrier-timeout on a link on interface *** is displayed, shutdown! Start enable-time may be used for correction, call conflict, or poor line quality.

If ISDN is used for dialing, use the debug isdn q921 and debug isdn q931 commands to enable the configuration debugging switch of the ISDN Router. If the RR frame is displayed, the physical connection and the Q.921 protocol run normally, then, you can view the Cause value of the Cause in the Q.931 message Disconnect, Release, and Release Complete to obtain the reason for the call to stop. Then, modify the Cause based on the specific reason. The minimum and maximum number lengths of vswitches are strictly determined when an ISDN Router is used for dial-up configuration. If the vswitch returns the Disconnect message after the Setup message of the call, and the Cause value of Cause is 9c, the call number is incorrect, check whether the minimum or maximum length configured for the ISDN Router is correct.

Call conflict

When the two routers initiate a call to the peer end at the same time, perform the following steps: Both ENDS initiate a call at the same time. If the peer end is being used, wait until the peer end hangs up; the two ends use an automatic call interval and initiate a call at the same time. You need to adjust the automatic dialing interval command dialer autodial-interval) or the two dialing enable time interval command dialer timer enable ), make the two ends of the interval inconsistent;

DCC interface load threshold Command dialer threshold 0 is configured on both ends. After a channel call is successful, the call from other channels should be UP almost simultaneously, but the call is uneven and irregular each time, even other channels may fail to call successfully. In this case, cancel the dialer threshold configuration at one end.

User authentication failed

The main caller has initiated a call. Use the debug dialer packet and debug dialer event commands to enable the DDR debugging switch and check that the call is normal. Use the debug ppp packet command to enable the PPP debugging switch, PPP packets are already sent and received. Perform the following steps for analysis: View PPP negotiation packets. If there are PAP or CHAP authentication packets, but the authentication process fails, run the "display current-configuration" command to check whether the username and password configured at both ends match. If the dialer route command configured in the dial-up port has the name option, check whether the user name corresponds to the peer IP address. For shared DCC, because the user name is used to distinguish each Dialer port, if it is used as the main caller, the ppp authentication command must be configured on the Dialer interface to require the Peer to send the user name and password. If DCC is shared as the called end, you must use the peer user name to find the parent interface, therefore, the ppp authentication command must be configured on the physical interface used by the shared DCC to require the Peer to send the user name and password.

IP address negotiation Error

The call starts and the PPP negotiation is successful, but the call is hung up. Perform the following analysis: Use the debug dialer event and debug dialer packet commands to enable the DDR debugging switch. If you see the prompt "DCC: peeraddr matching error on interface ***, shutdown link, the IP address of the Peer end is the same as the IP address configured by the local dialer map, so the call is rejected. Use the dialer string command to configure and solve the problem.

PPP call back failed

The Client side of the PPP call back is successful, but the Server side does not stop or call back. Perform the following analysis: Use the debug dialer event and debug dialer packet commands to enable DDR debugging. If "DCC" is not displayed: link layer transfer callback request with name ''and dialstring'' to DCC on interface "information, check whether the Client has configured the ppp callback client Command, or whether the ppp callback Server command is configured on the server.

If the message ": Link layer transfer callback request with name'' and dialstring ''to DDR on interface" appears, but "DCC: Ready to callback" is not displayed, disconnect the income-call first. "Information, you need to check whether the Server side has configured the dialer callback server command. If it is configured as dialer callback-center user, it indicates that the dialer route matches the username to call back; if dialer callback-center dial-number is configured, call back-dialstring in the local-user command. Therefore, check whether the corresponding call back dialing string exists and is correct. The ISDN Router configuration is received by the caller, but the call is not hung up and called back. Perform the following analysis: Use the debug isdn q931 and debug dialer event commands to turn on the debug switch, and the "DDR: Receive CALL_CONN_IND" and "DDR: receiveda Caller with ID ''in interface "information. If the ID is null or the ID is inconsistent with the ID configured by the dialer call-in on the Server, the callback fails. ISDN call-back requires the cooperation of the switch and must be configured on the switch to forward the caller number to the called end so that the call-back can be successful.

The call fails again after the call is hung up.

Use the debug dialer event and debug dialer packet commands to Enable the DDR debugging switch. The "DDR: Enable-timeout is valid, failed" prompt is displayed. To prevent too many calls, DDR requires that there must be an interval between two calls. If the message "DDR: Enable-timeout is failed, failed" is displayed, it means that the interval has not timed out. You only need to wait. If the setting takes a long time, you can use the dialer timer enable command to modify the settings.