...> ax25 <subcommands>

All AX.25 parameters are configurable per interface. This command sets the default or global values. Use ifconfig to set or show the interface-specific values.

ax25 alias <aliascall> The alias command shows or sets the system alias call. If netrom is enabled, this modifies the same call as the 'netrom alias' command. The 'ax25 alias' command is NOT needed in that case! If netrom is not used, this command allows an alias name to be set such that users can connect to it. The alias is typically a short string and should not be a valid callsign, since any SSID is ignored when matching against <aliascall> (6 char MAX). Example: 

  ax25 alias knx

ax25 bbscall [<bbs_call>] The bbscall subcommand sets or shows the current bbs callsign. Connects to this callsign, when set properly, will "jump-start" the mailbox. That is, after the connect no additional packet need be sent to obtain the mailbox greeting. This subcommand will automatically set the bbscall for all currently-attached AX.25-class interfaces with no bbscall set. For bbscall to function properly, it must differ from the system alias/netrom alias, as well as the link address of the interface (usually set by 'ax25 mycall'). See also 'ifconfig <iface> bbscall <bbs_call>'. Note that the bbscall value is also used for the source address of ax.25 connections initiated from the console, provided that the ax25 ttycall is not set, or that JNOS was *not* compiled with #define TTYCALL_CONNECT. #Example: (in the following order) 

ax25 mycall N5KNX-1
ax25 alias KNX
ax25 bbscall N5KNX
attach <(all interfaces)>
ifconfig <name> bbscall <bbscall>

sets only iface <name>

ax25 bc <iface> The bc command forces an immediate broadcast on the given interface. The particular interface or port must have been enabled with the ax25 bcport command first. If this is so, the ID will be broadcast as set with the ax25 bctext commands. 

ax25 bc port1

ax25 bcinterval [<seconds>] The bcinterval displays or sets the time in seconds between broadcasts. On display, both the interval and the countdown values are shown. Default = 600 (10 minutes).

ax25 bcport [<iface> [on | OFF]] Display or set the active interfaces for ax.25 broadcasting (i.e. beacons). If no interface is given, all interfaces with ax.25 beaconing enabled will be listed. If interface is given, the status of beaconing for that interface is shown, or set according to the following on or off option. Initial state is off. 

ax25 bcport port1 on

ax25 bctext broadcast text Display or set the default text to be sent for broadcast messages sent out every ax25 bcinterval seconds. To compose a multi-line message, use \r between the text of each line, ie, "line1\rline2". See also 'ifconfig <iface> bctext bctext. 

ax25 bctext This is the beacon text

ax25 blimit [<value>] Display or set the default AX25 retransmission backoff limit. Normally each successive AX25 retransmission is delayed by twice the previous interval; this is called binary exponential backoff. When (retrycount) reaches or ex-ceeds the blimit <value>, the retry interval is no longer increased. To prevent the possibility of "congestive collapse" on a busy channel, blimit should be set greater than the number of stations sharing the channel. Note this applies only on AX25 connections; UI frames are not acknowledged thus are not retransmitted. See also ax25 maxwait, and ax25 timertype. Default: 30 Example: Set ax25 blimit to 15 

ax25 blimit 15

ax25 dest [<iface>] Display the destinations saved in the heard list, for all interfaces with heard list maintenance enabled, or for the just the specified interface. See also "ax25 heard" and "ax25 filter N".

ax25 digipeat [<iface> [ON | off]] Display or enable/disable digipeating feature. If no interface is given, all interfaces with digipeating enabled will be listed. If interface is given, the status of digipeating for that interface is shown. If both <iface> and ON/OFF are given then the feature is set process or ignore digipeating requests. If cross-band or AXIP digipeating is to be allowed, digipeating must be enabled on both interfaces involved. Default is ON. Example: To display digipeat status of port1 

ax25 digipeat port1

ax25 filter N Default: 0 Sets the ax.25 heard list filtering value. This is a global value that affects all ports with heard list maintenance set to ON.

ax25 flush Clears the AX.25 "heard" list (see ax25 heard and ax25 hport)

ax25 heard [<iface>] Display the AX.25 "heard" list. For each interface that is configured to use AX.25 heard listing (see 'ax25 hport'), a list of all ax25_source addresses heard on that interface is shown, along with a count of the number of packets heard from each station and the time since each station was last heard. The maximum length of the heard table can be set with the 'ax25 hsize' command. If interface is given, only the heard list for that interface is displayed. 

ax25 heard port1

ax25 hearddest [<iface>] Same as "ax25 dest [<iface>]".

ax25 hport [<iface> [ON | off]] Display or set the status of the ax.25 heard feature. If no interface is given, all interfaces with ax.25 heard enabled will be listed. If interface is given, the status of ax.25 heard for that interface is shown, or set according to the following on or off option. Default is ON. Example: To display port1 status 

ax25 hport port1

ax25 hsize [<size>] Set or display the size of the heard list table. Default is 0 which means no limit.

ax25 irtt [<milliseconds>] Display or set the initial value of smoothed round trip time to be used when a new AX25 connection is created. The actual round trip time will be learned by measurement once the connection has been established. Default is 5000ms. Example: Set irtt to 10 seconds (10000 milliseconds) 

ax25 irtt 10000

ax25 kick (<axcb> | <CALL>) Force a retransmission on a specified AX.25 link to a remote station. This is useful to reactivate connections that have long time-out values. Beginning with version jnos2.0f the link may be identified by either the <axcb> (ax25 control block address) or the <CALL> of the remote station. Prior to the "f" release, only the <axcb> was valid. The list of links may be found using the ax25 status command.

ax25 maxframe [<count>] Establish the maximum number of frames that will be allowed to remain unacknowledged at one time on new AX.25 connections. This number cannot be greater than 7. Without <count> it will display the current setting. Note that the maximum outstanding frame count only works with virtual connections. UI frames are not affected. Also note that for optimal performance, a value of 1 should be used. Default is 1 frame.

ax25 maxwait [<msec>] Sets a limit (in msec) to the retry timeout values. Default = [TBD] 0 ?OR? 30000 (30 secs). A value of 0 disables maxwait.

ax25 mycall [<ax25call>] Display or set the default local AX.25 address. The standard format is used, (e.g. WG7J or KA7EHK-5). This command must be given before any attach commands using AX.25 mode are given. Example: 

ax25 mycall wg7j-3

ax25 paclen [<size>] This sets the default paclen used when attaching interfaces that will carry AX.25 connections. See also 'ifconfig <iface> ax25 paclen'. Default is 256 bytes. This parameter limits the size of I-fields on new AX.25 connections. If IP datagrams or fragments of datagrams larger than paclen are transmitted, they will be transparently fragmented at the AX.25 level, sent as a series of I frames, and reassembled back into a complete IP datagram or fragment at the other end of the link. IP datagrams will not be affected if this parameter is greater than or equal to the MTU of the associated interface.

ax25 pthresh [<size>] Display or set the poll threshold to be used for new AX.25 Version 2 connections. The poll threshold controls retransmission behavior as follows. If the oldest unacknowledged I-frame size is less than the poll threshold, it will be sent with the poll (P) bit set if a time-out occurs. If the oldest unacked I-frame size is equal to or greater than the threshold, then a RR or RNR frame, as appropriate, with the poll bit set will be sent if a time-out occurs. The idea behind the poll threshold is that the extra time needed to send a "small" I-frame instead of a supervisory frame when polling after a time-out is small, and since there's a good chance the I-frame will have to be sent anyway (i.e., if it were lost previously) then you might as well send it as the poll. But if the I-frame is large, send a supervisory (RR/RNR) poll instead to determine first if retransmitting the oldest unacknowledged I-frame is necessary; the time-out might have been caused by a lost acknowledgment. This is obviously a tradeoff, so experiment with the poll threshold setting. The default is 128 bytes, one half the default value of <paclen>

ax25 reset (<axcb> | <CALL>) This subcommand will immediately remove the AX.25 link to the specified remote station. This deletes a connection and everything associated with it. Beginning with version jnos2.0f the link may be identified by either the <axcb> (ax25 control block address) or the <CALL> of the remote station. Prior to the "f" release, only the <axcb> was valid. The list of links may be found using the ax25 status command.

ax25 retries [<count>] Limit the number of successive unsuccessful retransmission attempts on new AX.25 connections. If this limit is exceeded, link re-establishment is attempted. If the link can't be re-established in <count> times, then the connection is abandoned and all queued data is deleted. Default is 5.

ax25 route [<subcommand>] Without optional subcommands, display the AX.25 routing table that specifies the digipeaters to be used in reaching a given station.

ax25 status [<axcb> | <call>] Without an argument, the status subcommand will display a one-line summary for each AX.25 link. With an argument, when one particular link is identified, the contents of the control block are shown in detail. As of revision jnos2.0f the selected link may be specified by including either the <axcb> (ax25 control block address) OR the <CALL> of the remote station on the link. Prior to the "f" version, only the block address was valid.

Example(s): 

ax25 status
ax25 status 09e05cb0
ax stat J0NOS

The output may be interpreted from the headings per the table [tbd]:

ax25 t2 [<milliseconds>] Display or set the AX.25 "resptime" timer in connected mode to intentionally delay I-frame ACK packets. By delaying the transmission of packets, this timer eliminates some redundant transmissions and improves use of the communication channel by creating the possibility of adding ACKs to the next I-frame rather than sending an ack frame by itself. In datagram mode (UI) t2 has no meaning [see also mode command]. Value is in milli-seconds, the default is 1000ms (1 sec), and minimum is 0ms which effectively defeats t2.

ax25 t3 [<milliseconds>] Display or set the AX.25 idle "keep alive" timer. Value is in milliseconds. Default is 0, i.e. no 'keep-alive' polling.

ax25 t4 [<seconds>] Display or set the AX.25 Link "redundancy" timer. Value is in seconds. When no exchange has been had during this time the link is reset and closed. Default = 300 seconds (5 minutes).

ax25 timertype [type] Sets or displays the type of timer used for retransmission and recovery. Default is [TBD] linear ?OR? EXPONENTIAL.

Example: 

ax25 timertype exponential

ax25 ttycall [ttycall] Set or display the tty-link callsign for direct keyboard access. Set both 'attended on' and 'mbox attend on' to use this function. The ttycall value is also used for the source address of ax.25 connections initiated from the console, provided that JNOS was compiled with #define TTYCALL_CONNECT.

ax25 version [n] Display or set the version of the AX.25 protocol to attempt in making new connections. Version 1 is the version that does not use the poll/final bits. Default: 2

ax25 window [<size>] Display or set the number of bytes that can be buffered (pending processing) in an AX.25 receive queue. When exceeded, incoming I frames will be answered with RNR (Receiver Not Ready) responses. RNR is presently applied only to interactive AX.25 sessions, since I-frames containing network (IP, NET/ROM) traffic are processed immediately and are not placed on the receive queue. Default: Linux=2048 DOS=512 bytes

ax25 (last edited 2008-04-10 22:43:53 by GeorgeVerDuin)