Ham Radio 2000 #1

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Text File | 1996-06-14 | 16.6 KB | 415 lines

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 BEHAVIOUR 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>'. #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>] (B) 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. See also 'ifconfig <iface> beacon ["bctext"]. ax25 bctext "This is the beacon text!" ax25 blimit [<value>] Default: 30 (B) 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 ex- ceeds 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". 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, ie, 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 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>] (B) 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>] (B) 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>] (B) This sets the default paclen used when attaching interfaces that will carry AX.25 connections. See also 'ifconfig <iface> 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. Note2: see also the section 'Of PACLEN, MTU, MSS, and More' in the JNOS40 Configuration Manual. ax25 pthresh [<size>] (B) 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>] (B) 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. ax25 t3 [<milliseconds>] Default: 0 (B) 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 (B) 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] (B) 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 call for direct keyboard access. Remember to have both 'attended on' and 'mbox attend on' to be able to use this function. ax25 version [n] (B) 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 (B) 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.