Link Parameters

The parameters described in this section are located in the Link Editor window in x25tool.

The parameter values are stored in the link configuration files /etc/opt/SUNWconn/x25/config/link_config_nnnn.cfg, where nnnn is the four-digit number that indicates the link number (for example, the file link_config_0004.cfg contains the parameters for link number 4).

These parameters are used to configure a physical link.

Link Number

A number that identifies the link (which is a connection over a specific network interface). This can be either a PSDN or LAN. Each link must have a unique number. This number is used to identify which link is being configured in various parts of x25tool.

Link Description (description)

This is an optional field. Enter an alphanumeric string of 80 or fewer characters. Spaces are allowed.

Link Type (type)

Table 7-1 lists the available values:

Table 7-1 Link Type values

Value	Meaning
WAN (1988)	A connection to a WAN conforming to the 1988 version of the X.25 Recommendations.
WAN (1984)	A connection to a WAN conforming to the 1984 version of the X.25 Recommendations.
WAN (1980)	A connection to a WAN conforming to the 1980 version of the X.25 Recommendations.
LAN	A connection to a LAN.
MLP n - links	A multi-link protocol connection using n physical links.

Device (device)

The name of the link level device. Table 7-2 lists the available types:

Table 7-2 Device Types

Value	Meaning
ZSH	One of the onboard serial ports.
HSI	High Speed Interface. A serial port on the Solstice HSI/S SBus card.
EXPX	A serial port on the SCiiExpress-X card.
WLOOP	The loopback driver.
LE	An Ethernet interface on a SPARCstation.
IE	An Ethernet interface on a SPARCstation.
BE	A fast Ethernet interface.
QE	The SBus Quad Ethernet card.
SMC	A PC Ethernet interface.
EL	A PC Ethernet interface.
ELX	An Ethernet interface on the 3Com Etherlink III card. The default Ethernet interface type for a PC.
SMCE	A PC Ethernet interface.
SMCEU	A PC Ethernet interface.
IEE	A PC Ethernet interface.
HEE	A PC Ethernet interface.
IEEF	A PC Ethernet interface.
EEPRO	A PC Ethernet interface.
NEI	A PC Ethernet interface.
RI	A PC Ethernet interface.
XP	A PC Ethernet interface.
PCN	A PC Ethernet interface.
FDDI	An FDDI interface.
TR	A Token Ring interface.

For the x86 version of the product, the device type depends on the type of Ethernet card used by your PC. The default ELX-0 applies to the 3Com Etherlink III card. If IP is running, you can find out what device type your PC uses by entering the following command: Included in the information returned by this command is the name of the device that IP is running over. Use this same device type for X.25.

hostname% ifconfig -a

---

Note -

The list of device types available for the x86 version of the product is constantly being updated. Therefore, your PC may use a device that is not shown in Table 7-2. If this is the case, you can add the new device to the device types list in the Boards Definition window. See "Definition" for more information.

---

Port Number (device)

The port number of the LAN or WAN device used beneath X.25. The Device Type plus the Port Number must form a unique identifier for each link.

Tx Clock (line_speed)

Set this to either External, or specify the appropriate bit rate (in x25tool, you select the bit rate from the drop down menu). If you choose External, both the transmit clock and receive clock are set to external This means that the clocking speed is provided by a synchronous modem or modem eliminator.

If you specify a bit rate, this means that the local machine supplies the clocking, so make certain that the bit rate you select matches the transmission rate of the local machine.

Frame Window Sizes (locmaxwinsize, remmaxwinsize, locdefwinsize, remdefwindsize)

Window sizes can be in the range 1 to 7 for modulo 8 networks, or 1 to 127 for modulo 128 networks. The default must be less than or equal to the maximum.

Interface (mode)

This applies to WAN connections only. Choose between DTE and DCE. If you are connecting to a PSDN via a modem, the machine running the Solstice X.25 software is the DTE and the modem acts as the DCE. If you are connecting two machines back-to-back, make one the DTE and the other the DCE.

LAP Protocol (protocol)

This applies to WAN connections only. Choose between LAP, LAPB and LAPBE. Almost all PSDNs use LAPB.

Local X.121 Address (local_address)

For WAN interfaces this is your DTE or DCE address, normally an X.121 address, consisting of a DNIC, NTN, and, optionally, a subaddress. Your service provider should notify you of what this address is. A small number of public networks require that the calling address in an outgoing packet not contain the full X.121 address (for example, Transpac only requires the sub-address). In such a case, enter the "short" version of your X.121 address (as specified by your service provider) in this field. Your service provider will inform you if you need to do this.

For LAN interfaces, this is a six-byte (12 hexadecimal) digit address. The default of twelve zeroes tells Solstice X.25 to use your machine's default MAC address. To use the MAC address stored on an interface controller card (such as the address on the FDDI/S SBus card) enter the address as twelve consecutive hexadecimal digits or as pairs of hexadecimal digits, with colons between each pair and leading zeroes within pairs omitted.

Version (network)

The version of the X.25 Recommendation that your PSDN conforms to--1980, 1984, or 1988.

Packet Size (locmaxpktsize, locdefpktsize, remmaxpktsize, remdefpktsize)

Sets the packet size for all priority call requests and incoming calls. Possible values are: Default, 16, 32, 64, 128, 256, 512, 1024, 2048 and 4096.

---

Note -

In the configuration file, packet sizes are expressed as powers of 2. For example, to specify 128, enter 7.

---

Logical Channel Ranges (pvc_range, inc_range, out_range, two_range)

Consult your service provider to find out the correct logical channel ranges to use. For each type of virtual circuit you use, you must set the channel ranges so that they match the range of numbers specified by your PSDN. For back-to-back or LAN connections, you must match the logical channel numbers used by the remote hosts with which you intend to communicate. Mismatches between logical channel number ranges are frequently the cause of inability to establish connections. A common symptom of an LCR mismatch is that connections operate in one direction only.