Dual Basic Rate ISDN (DBRI) Chip (isdntest)

The isdntest verifies the functionality of the ISDN portion of the Dual Basic Rate ISDN (DBRI) chip.

The isdntest is actually a set of several subtests. Three main channels exist within an ISDN: D, B1 and B2. In each of the following subtests, unless otherwise indicated, the D channels are in Basic Rate HDLC data mode, the B1 channels are in 56 kbps HDLC data mode, and the B2 channels are in 64 kbps HDLC data mode. The D channel packet size is 256 bytes, and the B channel packet size is 1024 bytes. The packet count is 10 packets. Each channel runs as an independent thread.

Local Loopback Test The local loopback test checks the initial activation state of the Network Termination (NT) and Terminal Equipment (TE) interfaces to make sure they are deactivated. Then it activates each interface using the "force activation" capability of DBRI. Each interface is put into local loopback mode (See Figure 12-1). Data residing in host memory is written to each interface, which loops the data back to itself. The data is then read back into host memory and verified. Each channel, D, B1 and B2 is tested (with the exception of the TE D channel, which cannot be tested in local loopback mode). The local loopback test runs internal to the DBRI chip and does not require an NT-to-TE external loopback connector.

Figure 12-1 isdntest

Activation/Deactivation Test The activation/deactivation test runs through the activation/deactivation sequence for the NT and then the activation sequence for the TE. The T101 and T103 timers are set to five seconds. This subtest requires an NT-to-TE external loopback connector.

Remote Loopback Test The remote loopback capability is tested next. The TE interface is put into remote loopback mode, and the NT transmits data to the TE on all three channels, D, B1 and B2 (See Figure 12-2). The TE loops all data back to the NT and reads a copy of it. Data is then verified. Next, the whole process is repeated with the TE transmitting to the NT, which is placed in remote loopback mode. This subtest requires an NT-to-TE external loopback connector.

Figure 12-2 isdntest

Read/write Test Next, a read/write test is performed on all six ISDN channels: TE D, TE B1, TE B2, NT D, NT B1 and NT B2. The external loopback connector connects each channel on the TE interface to its corresponding channel on the NT (See Figure 12-3). A unique data pattern is used for each path. Packets read are compared against packets written. The test is repeated with the B1 channels placed in 64 kbps HDLC data mode and the B2 channels in 56 kbps HDLC data mode. This subtest requires an NT-to-TE external loopback connector.

Figure 12-3 isdntest

Packet Size Test The next subtest is a packet size test. A read/write test, similar to the previous one, is performed with a packet count of 100. Each packet transmitted and received is a unique size, computed randomly. This subtest requires an NT-to-TE external loopback connector.

Data Path Test The last subtest is a data path test. Using the ISDN_SET_CHANNEL ioctl, data is routed through a series of short pipe interconnects within DBRI (See Figure 12-4). This subtest requires an NT-to-TE external loopback connector.

Figure 12-4 isdntest

isdntest Options

Figure 12-5 isdntest

Packet Size Packet size indicates the byte size of the B channel packets. The default size is 1024 bytes for the B channels and 256 for the D channels. The maximum packet size is 8186 bytes for the B channels, and the minimum packet size is 1 byte. The D channel packet size is set to 256, except during the packet size test, when it is set to random values between 1 and 256.

Packet Count Packet Count indicates how many packets are to be transmitted and received for all channels. The default packet count is 10 packets. The maximum packet count is 100 packets.

isdntest Test Modes

Running this test in Connectivity or Online mode restricts testing to the local loopback subtest only.

isdntest Command Line Syntax

/opt/SUNWvts/bin/isdntest         standard_arguments -o size=packet_size,

count=packet_count

Argument	Explanation
size=packet_size	Specifies the byte size of the B channel packets B channel default size = 1024 bytes D channel default size = 256 bytes B channel maximum packet size = 8186 packets B channel minimum packet size = 1 packet D channel packet size = 256 (except during the packet size test, when it is set to random values between 1 and 256)
count=packet_count	Indicates how many packets are to be transmitted and received for all channels Default count = 10 packets Maximum packet count = 100 packets

isdntest Error Messages

The isdntest error messages are listed below with explanations or probable causes:

1. Unable to open <device_name>. (<error_message>)
  Device already being used.

2. Write failed for <device_name> during <subtest>.

(<error_message>)

3. Return value from write incorrect for <device_name>
    during <subtest>.
  Actual: <number>  Expected: <number>

4. Read failed for <device_name> during <subtest>.

(<error_message>)

5. Return value from read incorrect for <device_name>
    during <subtest>.
  Actual: <number>  Expected: <number>

6. Data miscompare for <device_name> during <subtest>.

7. Packet <number> size <number> offset <number> contains
    <number>, should be <number>.

Defective loopback cable.