JNOS Commands Manual - The A Commands
The A Command Set
abort [<session #>] Abort a FTP get, put or dir operation in progress. If issued without an argument, the current session is aborted. (This command works only on FTP sessions.) When receiving a file, abort simply resets the data connection; the next incoming data packet will generate a TCP RST (reset) response to clear the remote server. When sending a file, abort sends a premature end-of-file. Note that in both cases abort will leave a partial copy of the file on the destination machine, which must be removed manually if it is unwanted. arp Display the Address Resolution Protocol table that maps IP addresses to their subnet (link) addresses on subnetworks capable of broadcasting. For each IP address entry the subnet type (e.g., AX.25), subnet address and time to expiration is shown. If the link address is currently unknown, the number of IP datagrams awaiting resolution is also shown. arp add <hostid> ax25 | netrom <callsign> <iface> or arp add <hostid> ether | ax25 | netrom | arcnet <ether_addr>|<callsign> <iface> Add a permanent entry to the table. It will not time out as will an automatically created entry, but must be removed with the 'arp drop' command. arp add 44.26.0.19 ax25 wg7j-2 port1 arp drop <hostid> ax25 | netrom <iface> or arp drop <hostid> ether | ax25 | netrom | arcnet <iface> Delete a permanent entry from the arp table. arp delete 44.26.0.19 ax25 port1 arp eaves [<iface>] [on | OFF] Display or set the 'arp eavesdrop' function per interface. If set, all arp replies overheard on the interface will be logged in the arp table. This speeds up arp discovery, but might build a huge arp table taking up lots of memory. Default for each interface is off. # Set arp eavesdrop on interface port1 arp eaves port1 on arp flush Drop all automatically-created entries in the ARP table; permanent entries are not affected. arp maxq [n] Display or set the maximum number of packets to be buffered waiting for an arp resolution to finish. Default = 5. arp maxq 5 arp poll [<iface>] [on | off] Display or set the 'arp keepalive polling' per interface. If set, when an arp entry expires, a query will be sent for the address. This keeps the arp table fresh, but possibly retains many unneeded entries. arp poll port1 on arp publish <hostid> ax25|netrom <callsign> <iface> This command is similar to the 'arp add' command, but the system will also respond to any ARP request it sees on the network that seeks the specified address. (Use this feature with great care!) arp publish 44.26.1.19 ax25 wg7j-2 port1 arp sort [ON | off] Sorts the arp display. asystat Display statistics on attached asynchronous communications interfaces (8250 or 16550A), if any. Example: tnc: [NS16550A] [trigger 0xc0] [rlsd line control] 19200 bps [@ 3f8,4] RX: 929462 int, 3683653 chr, 0 hw over, 6 hw hi, 17210 fifo TO, 0 sw over, 126 sw hi TX: 946381 int, 7400204 chr, 0 q, 79401 MS int, 40 THRE TO tnc2: [NS16550A] [trigger 0xc0] 9600 bps [@ 2f8,3] RX: 722895 int, 2865467 chr, 0 hw over, 8 hw hi, 13075 fifo TO, 0 sw over, 248 sw hi TX: 246420 int, 1889156 chr, 0 q, 1 MS int, 16 THRE TO The display for each port consists of three lines. The first line gives the port label and the configuration flags; these indicate whether the port is a 16550A chip, the trigger character if any, whether CTS flow control is enabled, whether RLSD (carrier detect) line control is enabled, the speed in bits per second, and the port address and IRQ number in hexadecimal. (Receiving the trigger character causes the driver to signal upper layer software that data is ready; it is automatically set to the appropriate frame end character for SLIP, PPP and NRS lines.) The second line of the status display shows receiver (RX) event counts: the total number of receive interrupts, received characters, receiver overruns (lost characters) and the receiver high water mark. The high water mark is the maximum number of characters ever read from the device during a single interrupt. This is useful for monitoring system interrupt latency margins as it shows how close the port hardware has come to overflowing due to the inability of the CPU to respond to a receiver interrupt in time. 8250 chips have no FIFO, so the high water mark cannot go higher than 2 before overruns occur. The 16550A chip, however, has a 16-byte receive FIFO which the software programs to interrupt the CPU when the FIFO is one-quarter full. The high water mark should typically be 4 or 5 when a 16550A is used; higher values indicate that the CPU has at least once been slow to respond to a receiver interrupt. When the 16550A is used, a count of FIFO timeouts is also displayed on the RX status line. These are generated automatically by the 16550A when three character intervals go by with more than 0 but less than 4 characters in the FIFO. Since the characters that make up a SLIP or NRS frame are normally sent at full line speed, this count will usually be a lower bound on the number of frames received on the port, as only the last fragment of a frame generally results in a timeout (and then only when the frame is not a multiple of 4 bytes long.) Finally, the software fifo overruns and high water mark are displayed. These indicate whether the <bufsize> parameter on the attach command needs to be adjusted (see the Attach Commands chapter). The third line shows transmit (TX) statistics, including a total count of transmit interrupts, transmitted characters, the length of the transmit queue in bytes, the number of status interrupts, and the number of THRE timeouts. The status interrupt count will be zero unless CTS flow control or RLSD line control has been enabled. The THRE timeout is a stopgap measure to catch lost transmit interrupts, which seem to happen when there is a lot of activity (ideally, this will be zero). The "asystat" command for UNIX JNOS is somewhat different from the DOS version. Example: 144.99: cua0, 9600 bps, packet size 255, RTS/CTS disabled, carrier disabled RX: ints 2 chars 73 puts 2 rxqueue 5 qlen 0 ovq 0 block 0 buf 1024 TX: ints 1 chars 57 gets 0 txqueue 2 qlen 0 ovq 0 block 0 linux: ttype, 38400 bps, non-blocking, RTS/CTS disabled, carrier disabled RX: ints 0 chars 0 puts 0 rxqueue 2 qlen 0 ovq 0 block 0 buf 1024 TX: ints 0 chars 0 gets 0 txqueue 2 qlen 0 ovq 0 block 0 ints is the number of times pwait() returned control to the rx or tx task, indicating that select() detected pending data on input or a packet became available for output. chars is the number of characters read/written. puts number of times received data was placed in the packet Hopper. gets number of times data was taken out of the send queue and written to the device. rxqueue is described in the asyconfig command helpfile. txqueue is described in the asyconfig command helpfile. qlen is the instantaneous queue size (number of packets). ovq is the number of times queue flow control (described in asyconfig) was triggered. block is the number of times read/write tried to block (in the case of reads, the number of times it tried to block after data was claimed to be available). buf is the current receive buffer size, as specified in the attach statement or the "asyconfig" command. at The 'at' command is used to provide automatic starting of other JNOS commands at predetermined times. at This form displays each scheduled at command and its id number, so that 'at kill n' can be used (see below). at time <cmd> time takes the form yymmddhhmm (specific date/time) hhmm (next occurrence of this time) whhmm (next occurrence of this time on specified weekday. 0=Sun,1=Mon, ..., 6=Sat) mm (mm mins after next hour) now+hhmm (offset from present time) <cmd> is any legal JNOS command. Multiple word commands must be enclosed in double quotes (" "). Commands which invoke the DOS shell must include '!' or shell as the first word in order for JNOS to recognize that an external command is to be invoked. If the external command requires the command processor, then "/c" may be given as the second word. Example: "! /c x.bat>> e:foo". To automatically reissue the at command when the timer matures, append a "+" character to the <cmd> string. Example: at 0130 "! cleanup+" Example: at now+0100 "ax25 flush+" Example: at 0600 "writeall \"Il est 6h00 GMT\"+" at k <id_num> [<id_num>...] This form of the 'at' command kills (i.e., deletes) jobs <id_num>... attach attach <hw_type> <io_addr> <vector> <mode> <label> <bufsize> <mtu> [<speed>] Configure and attach a hardware interface to the system. Detailed instructions for each driver are in the Attach Commands chapter. An easy way to obtain a summary of the parameters required for a given device is to issue a partial attach command (e.g., attach asy). This produces a message giving the complete command format. <hw_type> is the kind of I/O device being attached to the system. Choices include asy, kiss, packet, netrom, scc... <io_addr> is the base address of the control registers for the device. <vector> is the interrupt vector number. Both the address and the vector must be in hexadecimal. You may put "0x" in front of the numbers, but they will be interpreted in hexadecimal even without the prefix. <mode> controls how IP datagrams are to be encapsulated in the device's link level protocol. Choices include ax25, slip, pkiss, nrs, ppp... slip Encapsulates IP datagrams directly in SLIP frames without a link header. This is for operating point-to-point lines and is compatible with 4.2BSD UNIX SLIP. ax25 Similar to slip, except that an AX.25 header and a KISS TNC control header are added to the front of the datagram before SLIP encoding. Either UI (connectionless) or I (connection- oriented) AX.25 frames can be used. pkiss Similar to ax25, except that packets are checksummed and the interfaced devices are queried (polled) regularly for data. Used by G8BPQ polled-kiss software. nrs Similar to ax25, except that packets are transmitted only when permitted by flow-control signals. Typical of Netrom node stacks using Netrom serial protocol. ppp Similar to slip, except the protocol is different and typically is capable of compression. <label> defines the name by which the interface will be known to various commands, such as "connect", "route", "trace", etc. <bufsize> For ASYNCHRONOUS PORTS, specifies the size of the ring buffer in bytes to be statically allocated to the receiver, incoming bursts larger than <bufsize> may cause data to be lost. For ETHERNET, specifies how many PACKETS may be queued in the receive queue at one time. Excess packets will be discarded as they are received. This is useful to prevent the system from running out of memory should another node suddently develop a case of diarrhea. <mtu> is the Maximum Transmission Unit size in bytes. See the section 'Of PACLEN, MTU, MSS, and More' in Appendix D forr a discussion of the effect of MTU on system performance. attach asy <io_addr> <vector> <mode> <label> <bufsize> <mtu> [<speed>] [<flags>] Configure and attach a standard PC asynchronous I/O port using the National 8250, 16450, or 16550(A) chip or equivalent to the system, where: <io_addr> is the comm port address; e.g., com1 = 0x3f8 <vector> is the comm port IRQ value. If it is suffixed by "_C" then the interrupt service routine for this port is chained to the server list for this IRQ. <mode> one of: slip, ax25, ppp, pkiss, nrs <flags> string of characters, specifying options: c - do BPQ checksumming of ax.25 kiss packets v - do Van Jacobson TCP header compression on slip intfc f - force use of 16550a uart features (eg UM16C550 chip) fN - set 16550a trigger level to N (1,4,8, or 14. Default=4) n - use NRS-CTS protocol on nrs interface Flag for_mode #define_needed_in_config.h c ax25 AX25 and POLLEDKISS v slip SLIP and VJCOMPRESS n nrs NRS f (any) ASY The UNIX version of "attach asy" is slightly different, such that: <io_addr> is the Unix device name, e.g., cua0 or ttyS2. <vector> is ignored presently. <flags> include c,v,f, and n. The fifo trigger level flag, "fN", is reinterpreted as providing a packet size. The value can range from 0 to 255; if it is 0, the original input mechanism is used, otherwise blocking reads are used with termios VMIN set to the specified value. At the moment there is no error checking; if you set the buffer size smaller than VMIN you could lose incoming data. Under some unix versions, setting it to anything other than a multiple of VMIN could cause problems. The tradeoff here is that when the VMIN mechanism is used, input could be delayed by up to 1/5 second on a mostly quiet channel, but on an active channel JNOS will use *much* less CPU time and generally will be much more efficient. attach axip <iface> <mtu> <ipaddress> [<callsign>] Create a RFC1226 compatible AX.25 frame encapsulator for transmission of AX.25 frames over the IP. This command is used to establish a point-to-point AX.25 'tunnel' between two systems. <iface> will be the name of the new interface, <mtu> is the maximum transmission unit for the interface, <ipaddress> is the address of the system on the other side of the 'tunnel, <callsign> is the optional AX.25 callsign this station is listening on for frames to digipeat. Note that if you want cross-tunnel digipeating to work, each attached axip interface should listen to a different callsign. These should also be different from other callsigns used on this station. attach axip axip1 256 44.26.1.19 WG7J-15 attach kiss <asy_iface_label> <port> <label> [mtu] Attach a second kiss interface on the serial port. This command allows the use of multiport TNCs. The first port should be attached by a prior "attach asy ..." command with <mode> set to ax25 or pkiss. Use pkiss if G8BPQ polled kiss mode is desired. It is up to the tnc's firmware to select which port is at what baud. For example, the KPC9612 uses the MYDROP command for this purpose. <asy_iface_label> is the name of the serial port interface. <port> is the port number (1-15) to use, and probably should be 1. (the original asy port is automatically port 0 !) <label> is the name for this second kiss port. <mtu> is an optional mtu, if different from the mtu on the first kiss port. # Attach a dualport tnc in kiss mode. # Ports are labelled 'port1' and 'port2' # Attach a PC asynch port (com1 in this example) attach asy 03f8 4 ax25 port1 512 256 9600 # Attach the second port on the multiport tnc attach kiss port1 1 port2 attach netrom This makes available a pseudo interface to enable NET/ROM operations. This command is automatically executed when the netrom server is started with the 'start netrom' command. attach packet <softintr#> <iface_label> <maxqueue> <mtu> [ipaddress] Driver for use with separate software "packet drivers" which conform to the FTP Software, Inc., Software Packet Driver specification. See the Crynwr (TM) packet driver collection at ftp.crynwr.com, if your hardware (e.g. ethernet card) came without a packet driver. [ipaddress] is an optional ip address for the interface. If not set, the system 'ip address' will be used. Note that the packet driver is often loaded as a TSR in config.sys or autoexec.bat. It is the driver that must be supplied with information such as hardware IRQ, i/o address, and software IRQ. JNOS only needs to know the software IRQ value to interact with this driver. You must pick a software IRQ that is otherwise unused. Values between 0x78 and 0x7f are often suitable. Example: attach packet 0x7e eth0 5 1500 attach scc AND attach escc G8FSL/PE1CHL driver for generic Z8530 cards, including DRSI cards. Use escc if the Z85230 chip is installed, otherwise use scc. Specify only one 'easy' or one 'init' command, and as many 'mode' commands as required. attach scc <board label> baycom|drsi|opto <base address> <interrupt number> [t<timing channel>] attach scc <board label> <#chips> init <base address> <spacing between SCC chip base addresses> <offset to channel A control register> <offset to channel B control register> <offset from each channels control register to data register> <address of INTACK/Read Vector port. (0 to read from RR3A/RR2B)> <CPU interrupt vector number> <clock frequency (PCLK/RTxC) prefix with "p" for PCLK> <optional hardware type> <optional parameter for special hardware> <optional t<tick chan> specification to use a channel to improve timing> attach scc <board label> <SCC channel number to attach, 0/1 for first chip A/B> <mode, can be "slip", "kiss", "ax25" or "nrs"> <interface label> <maximum transmission unit, bytes> <interface speed, e.g, "1200". prefix with "d" when an external divider is available to generate the TX clock.> <buffer size> <optional callsign used on radio channel> <optional s flag to specify software-derived DCD detection> Example: (see sccg8fsl.txt and scc.c, in JNOS src zipfile, for more info) attach scc scc0 drsi 300 7 (easy form of init command which follows) attach scc scc0 1 init 300 16 2 0 1 0 7 p4915200 8 attach scc scc0 0 ax25 vhfa 235 d1200 512 k5arh-3 s attach scc scc0 1 ax25 vhfb 235 d1200 512 k5arh-2 s attach bpq init <vec> <stream> attach bpq <port> <label> [<mtu> [<callsign>]] The JNOS BPQ driver allows JNOS to attach interfaces directly to bpqcode without having to use the packet driver interface and the nodedrv4.com TSR. JNOS will talk to bpqcode using the bpq_host interrupt code in version 4.00 and up of bpqcode. This eliminates the extra memory and processing time used by nodedrv4.com to send packets between JNOS and bpqcode. The "attach bpq init" sub-command attaches the bpq_host TSR driver, which is accessed via software interrupt <vec> (in hex) for BPQ stream <stream> (in decimal). "attach bpq init" may only be called once. The second form of the "attach bpq" sub-command is called once per <port>. It associates a BPQ <port> number with an interface name <label>. <mtu> may not exceed 256, and defaults to the ax.25 paclen value. <callsign> defaults to the ax25 mycall value, and establishes the callsign used by this BPQ port. attended [off | on] Displays or sets the global "I am present" flag in JNOS. This flag is used in the welcome header for incoming ttylink connections. axui <iface> [<unproto_call> [digipeater_string]] The axui command allows the console user to create a session that sends UI (unproto) packets to <unproto_call> via interface <iface>, from lines entered at the keyboard, and displays received UI packets. A split-screen session is created where possible. The default <unproto_call> is "ID". At most one axui session is permitted. AXUISESSION must be #define'd in config.h to enable this command. An axui session also allows a few commands, which begin with '/' in column 1: /c newcall change the unproto call to <newcall> /i iface change to interface <iface> /? or /h display a help message /t toggle display of the time a packet was received /q, /b, /e close the axui session Example: To use digipeater n5knx-5 for a local ARES unproto net, type: axui ax0 ares n5knx-5 ax25 <subcommands> All AX.25 parameters are configurable per interface. Commands of the form 'ax25 <command>' set the default or global values. Use the 'ifconfig <iface> ax25 <command>' form to set or show the interface-specific values. To set the system default ax.25 parameters, you must do so BEFORE attaching interfaces. After attachment, you must use the 'ifconfig <iface> ax25' command form to show or change values for that interface. THIS IS A CHANGE FROM THE BEHAVIOR EXHIBITED PRIOR TO JNOS VERSION 1.10X16, RELEASED 08FEB94. ax25 alias <aliascall> The alias command shows or sets the system's 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>. 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 TTYCALL_CONNECT #define'd. #Example: (in the following order) 'ax25 mycall N5KNX-1' 'ax25 alias KNX' 'ax25 bbscall N5KNX' 'attach <(all interfaces)>' or '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>] Default: 30 Display or set the default AX25 retransmission backoff limit. Normally each successive AX25 retransmission is delayed by twice the value of the previous interval; this is called binary exponential backoff. When 2^(retrycount) reaches or exceeds the blimit <value>, the retry interval is no longer increased. To prevent the possibility of "congestive collapse" on a loaded channel, blimit should be set at least as high as the number of stations sharing the channel. Note that this is applicable only on actual AX25 connections; UI frames will never be retransmitted by the AX25 layer. See also ax25 maxwait, and ax25 timertype. # 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 set digipeating per interface. 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, or set according to the following on or off option. If cross-band or AXIP digipeating is to be allowed, digipeating must be enabled on both interfaces involved. Default is on. # 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. 0 => log both source and destination callsigns 1 => do not log source callsign 2 => do not log destination callsign 3 => do not log any callsign, i.e., disable all heard list updates 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. # 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. #Set irtt to 10 seconds (10000 milliseconds) ax25 irtt 10000 ax25 kick <axcb> Force a retransmission on the specified AX.25 control block. The control block address can be found with the ax25 status command. This is useful to reactivate connections that have long time-out values. 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 = 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. 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. If NET/ROM communication is configured, the NetRom MTU value should be Paclen - 20. !!! The Net/Rom header takes 20 bytes, and is part of the AX25 data. Default netrom mtu is 236. Note1: the AX.25 Level 2 Version 2 definition specifies a maximum paclen of 256 bytes. Some systems are not equipped to handle larger packets (e.g. G8BPQ based systems), so be careful when using this parameter. 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> Delete the AX.25 connection control block at the specified address. This deletes a connection and everything associated with it. The control block address can be found with 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 route add <target> <iface> [[via] digis ...] ax25 route perm <target> <iface> [[via] digis ...] Add an entry to the AX.25 routing table. The route added may be replaced automatically by a new one, unless "perm" is used instead of "add". Replacement may occur when digipeaters are specified in an AX25 link from the node or a connection is received from a remote station via digipeaters. Such automatic replacement is usually desirable; use "route add perm ..." to prevent this where necessary. <target> is the destination call to reach via digipeaters. <iface> is the interface to use for this route, i.e. JNOS allows different digi routes for different interfaces. [digis...] is a list of one or more digipeaters, separated by spaces and/or commas. The keyword "via" is optional. ax25 route add k7uyx-1 port1 wg7j wa7tas n7dva ax25 route perm k7uyx-1 port1 wg7j wa7tas n7dva ax25 route drop <target> <iface> Drop an entry for <target> from the AX.25 routing table. ax25 route drop k7uyx-1 port1 ax25 route mode <target> <iface> [vc|dg|interface] Sets the interface ip mode to one of vc | datagram | interface for target. This indicates how ip links to the destination call <target> should be established. If nothing is given for a certain destination or target, the interface default mode is used, which defaults to datagram. (See also the 'mode' command). vc is a virtual circuit (ax25 connected mode, meaning that ip frames are sent using ax.25 connections) datagram is unconnected mode, (AX25 UI frames). interface is the default interface mode, as set with the 'mode' command. ax25 route mode k7uyx-1 port1 vc ax25 status [<axcb>] Without an argument, display a one-line summary of each AX.25 control block. If the address of a particular control block is specified, the contents of that control block is shown in more detail. Note that the send queue units are frames, while the receive queue units are bytes. ax25 t2 [<milliseconds>] Default: 1000 Display or set the AX.25 "resptime" timer. Value is in milli- seconds. Default is 1000ms, and minimum is 0ms. This timer lets JNOS eliminate some redundant transmissions and optimize what it sends by possibly adding ACKs to I-frames, by delaying the trans- mission of packets. A value of zero disables the use of the t2 timer, as does the use of datagram mode (UI) [see mode command]. ax25 t3 [<milliseconds>] Default: 0 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>] Default: 300 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 [LINEAR|exponential|original] Sets or displays the type of timer used for retransmission and recovery. Linear means that each retry will use a time-out that is RTT greater then the previous time-out. I.e. 4 sec, 8 sec, 12 sec, 16 seconds etc. Exponential means that each retry will use a time-out that is twice as large as the previous time- out. I.e. 4 seconds, 8 seconds, 16 seconds, 32 seconds etc. Original means that each retry will use a time out that is twice the RTT, i.e. 4 seconds, 8 seconds, 8 seconds, 8 seconds, etc. Default is linear. ax25 timertype exponential ax25 ttycall [ttycall] Set or display the tty-link callsign for direct keyboard access. Remember to have both 'attended on' and 'mbox attend on' to be able 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 TTYCALL_CONNECT #define'd. ax25 version [n] Display or set the version of the AX.25 protocol to attempt to use on new connections. Version 1 is the version that does not use the poll/final bits. Default is version 2. ax25 window [<size>] Default: 512 bytes Set the number of bytes that can be pending on an AX.25 receive queue beyond which I-frames will be answered with RNR (Receiver Not Ready) responses. This presently applies only to suspended interactive AX.25 sessions, since incoming I-frames containing network (IP, NET/ROM) packets are always processed immediately and are not placed on the receive queue. However, when an AX.25 connection carries both interactive and network packet traffic, an RNR generated because of backlogged interactive traffic will also stop network packet traffic from being sent.
(Courtesy KBNorton Computer Services)