Novell Documentation: Novell Internet Access Server 4.1

Troubleshooting Checkpoints

To isolate and resolve problems with X.25 links, complete the following steps:

Verify that the X.25 software and drivers are installed properly.

You can enter the MODULES command at the console and check the version number of each X.25 module and driver (such as SYNCPLUS.LAN, NW2000.LAN, and ARTIC.LAN).

Load X25CON and select X.25 Network Interface.

Make sure that the X.25 Network Interface window displays all configured X.25 interfaces. If the X.25 Network Interface window does not display all configured X.25 interfaces, identify the cause of the problem and correct it (refer to Common Problems).

Check whether the Physical layer, the Link layer, and the Packet layer of each interface are in the Up state.

If they are not in the Up state, identify the cause of the problem and correct it (refer to Common Problems).

Check the status of each LAN protocol connection using CALLMGR.

If all connections are established, then go to Step 11. Otherwise, continue with Step 5.

Select Ping Remote System.

Perform an X.25 PING test to the destinations to which the connection cannot be established.

Verify whether a call is established successfully within reasonable delay.

Verify whether the messages are transmitted and received error free.

Verify whether the average delay for a message's round trip is reasonable.

Verify whether the call is cleared successfully.

Load NIASCFG and select Bindings (parameter path: Select Configure NIAS > Protocols and Routing > Bindings). Check the binding of the LAN protocol to a WAN Interface.

Make sure that the Permanent WAN Call Destination field is specified at both ends if the associated virtual circuit is a PVC. You must ensure that the Authentication option is enabled if the Call Type option of the associated X.25 Call Destination is set to
On-Demand.

Load CONLOG, if it is not loaded, and enter REINITIALIZE SYSTEM at the console.

Enter CONFIG at the console and verify that the specific LAN protocol is bound to the correct WAN.

If it is not, examine the console log and correct the problem.

Check the status of each LAN protocol connection using CALLMGR.

If a connection is not established, then select the Cleared Circuit Summary of X25CON and check whether the call has been rejected by the Packet layer.

If the call has been rejected, correct the problem according to the cause code and diagnostic code (refer to Table 5 and Table 6) and return to Step 7. If no calls have been rejected, then check the LAN protocol configuration on the local and remote routers. If you find compatibility problems, correct them and then return to Step 7. If you do not find any problems, continue with Step 11.

Select X.25 Active Virtual Circuit and check whether the data packets are exchanged.

Cause Codes

Table 5 describes the meaning of each X.25 cause code.

Table 5. X.25 Cause Codes

Cause Code	Description
1(0x01)	Number busy. This cause code indicates that the data link between the local DTE and the network is not operational.
9(0x09)	Out of order. This cause code indicates that the data link between the remote DTE and the network is not operational.
17(0x11)	Remote procedure error. This cause code indicates that the virtual circuit was cleared because of a procedure error caused by the remote DTE. More specific information can be obtained by examining the diagnostic code.
25(0x19)	Reverse Charging acceptance not subscribed. The call was cleared because the Reverse Charging facility is requested while the called DTE does not subscribe to the Reverse Charging acceptance facility. This problem should occur only when the calling DTE requests the Reverse Charging facility.
41(0x29)	Fast Select acceptance not subscribed. This cause code indicates that the calling DTE includes the Fast Select facility in the Call Request packet while the called DTE does not subscribe to the Fast Select acceptance facility. When a call is cleared with this cause code, the Fast Select option should be disabled from the associated WAN call destination database.
3(0x03)	Invalid facility request. This cause code indicates that the invalid facility is included in the Call Request packet or Call Accept packet. More specific information can be obtained by examining the diagnostic code.
11(0x0b)	Access barred. This cause code indicates that the call setup is requested on the line on which the virtual circuit call setup is prohibited.
19(0x13)	Local procedure error. This cause code indicates that the virtual circuit was cleared because of a procedure error caused by the local DTE. More specific information can be obtained by examining the diagnostic code.
5(0x5)	Network congestion. The call is cleared with this cause code when the network is saturated. Because this situation is temporary, we highly recommend that you retry later.
13(0xd)	Not obtainable. The network rejects a call with this cause code when the destination DTE is disabled. Therefore, if a call is cleared with this cause code consistently, we highly recommend that you check the current status of the remote DTE.

Diagnostic Codes

Table 6 describes the meaning of each X.25 diagnostic code.

Table 6. X.25 Diagnostic Codes

Diagnostic Code	Description
34(0x22)	Call on one-way logical channel. Check that the LCN range assignments are the ranges agreed on with the network. If necessary, use NIASCFG to configure the correct values.
39(0x27)	Packet too long. Check whether the following conditions exist: 1. The default packet size is the one agreed on with the network. If this diagnostic is received in a Reset Request packet, use NIASCFG to configure the correct value. 2. The user data size of the Call Request packet exceeds 16 bytes without enabling the FSF option, or the User Data field is present in the Call Accepted /Call Connected packet but the FSF is not specified. In this case, the FSF option should be enabled, if it is allowed, or the WAN call destination database should be configured to reduce the User Data Size value.
42(0x2A)	Packet type not compatible with facility. The call is cleared with this diagnostic code when the called DTE attempts to accept an incoming call with the Response option set to Fast Select. This option should not be used in the NetWare environment.
49(0x31)	Call Request timer expired. A call can be cleared with this diagnostic code under the following circumstances: 1. Incompatible LCN assignment; therefore, the call request/incoming call is ignored by the network or the called DTE. 2. The called DTE is too busy to respond to the incoming call within the specified T21 timeout value. In this case, the calling DTE should increase the T21 timeout value.
65(0x41)	Facility Code not allowed. A call is cleared with this diagnostic code when an invalid facility is included in the Call Request packet or Call Connected packet. Examples are as follows: 1. An unknown facility is specified in the Call Request packet or the Call Connected packet. 2. Duplicate Closed User Groups are specified, such as CUG and BCUG, or CUG and CUGOA. 3. Fast Select, Reverse Charging, or CUG Facility is specified in the Call Connected packet. 4. Window Size Negotiation is specified and the ITU-T (International Telecommunication Union, Telecommunication Standardization Sector), previously CCITT, 1976 version is supported. 5. Closed User Group Facility is specified where this option is not allowed. 6. NUI is specified in the ITU-T 1976 and 1980 versions.
66(0x42)	Invalid facility parameters are specified. This diagnostic code indicates the call was cleared because invalid facility parameters are included in the Call Request packet or Call Connected packet. Examples are as follows: 1. The requested window size or packet size is greater than the maximum window size or packet size allowed, respectively, and flow control negotiation is not allowed. 2. An invalid packet size is specified for the specified ITU-T version. The maximum packet size was 1,024 bytes up to and including the ITU-T X.25 1980 version. It was increased to 4,096 bytes in the ITU-T X.25 1984 version. 3. An invalid packet size that is greater than 7 is specified for the ITU-T X.25 1976 version. 4. The requested throughput is greater than the maximum allowed, and the throughput negotiation is not allowed.
68(0x44)	Invalid calling DTE address. This diagnostic code indicates that the Calling DTE address included in the Call Request packet is invalid. Check with the network whether the specified local DTE address is correct. If necessary, modify the calling DTE address using NIASCFG.
71(0x47)	No logical channel available. This diagnostic code indicates that the total number of virtual circuits exceeds the maximum number of virtual circuits configured. Therefore, increase the maximum number of virtual circuits of the associated line.
72(0x48)	Call collision occurred. Usually, a call collision occurs when insufficient LCNs are allocated for SVCs. Therefore, when a call is cleared with this diagnostic code, we highly recommend assigning more LCNs for SVCs.
77(0x4d)	Invalid ITU-T-specified DTE facility. This diagnostic code indicates that the size of the Called or Calling Address Extension Facility exceeds the maximum size allowed (40 digits for 1988 version, 32 for 1984 version).
146(0x92)	Data Retransmission Timer (T25) expired. This problem occurs under the following circumstances: 1. The Maximum Receive Buffer Size is configured smaller than the packet size. Therefore, the incoming data packets are dropped by the driver. In this case, an exceptionally high number of reject frames are transmitted or received. 2. The T25 timeout value is too small; therefore, the timer expired. When you configure the T25 timeout value, consider the anticipated delay.
166(0xa6)	D-bit procedure not supported. This diagnostic code indicates that a Call Request packet or a data packet with the D-bit set was received where it is not allowed.
240(0xF0)	Normal termination. The SVC has been cleared per the upper layer's request.
241(0xF1)	Out of resources. The incoming packet is rejected because the local DTE is running out of resources.
242(0xF2)	Authentication failure. The call is rejected with this diagnostic code when the authentication fails. Make sure the calling address is in the Authentication Database of the associated interface and try again.
243(0xF3)	Inbound user data too large. The size of the incoming user data is greater than the configured Maximum Physical Receive Packet Size value or the configured User Data Size value.
244(0xF4)	Idle timer expired. This diagnostic code indicates that the call is cleared because the Idle Line Timer expired. The Idle Line Timer is active only when the associated Call Type is set to On Demand. Both parameters can be configured with NIASCFG.