X-Git-Url: http://gb7djk.dxcluster.net/gitweb/gitweb.cgi?a=blobdiff_plain;f=techdoc%2Fprotocol.pod;h=1a01737644f318c50a95c13cee86398b89431eaa;hb=f668b435207db36cefef7962e90f1973851ed2b5;hp=6a56b6389d1e5d680f10c5008a3a2be1ea8a5acf;hpb=6c8062c1356fe49974da2df121852b41971f7b77;p=spider.git diff --git a/techdoc/protocol.pod b/techdoc/protocol.pod index 6a56b638..1a017376 100644 --- a/techdoc/protocol.pod +++ b/techdoc/protocol.pod @@ -1,12 +1,13 @@ +# -*- perl -*- =head1 NAME -DXSpiderWeb Orthogonal Communications Protocol +Aranea Orthogonal Communications Protocol $Revision$ =head1 SYNOPSIS - ,,,,,|,... + ,,,|,... =head1 ABSTRACT @@ -32,7 +33,7 @@ for inter-node communications. =head1 DESCRIPTION This protocol is -designed to be an extensible basis for any type of one to many +designed to be an extensible basis for any type of one too many "instant" line-based communications tasks. This protocol is designed to be flood routed in a meshed network in @@ -65,9 +66,70 @@ can only be sent escaped. This is described further in the L and L. Most of this document is concerned with the L, however -some L which all implementation should issue and +some L which all implementations should issue and must accept are described. +=head1 Applications + +In the past messaging applications such as DX Cluster software have maintained +a fairly strict division between Ls and Ls". This protocol attempts +to get away from that distinction by allowing any entity to connect to any +other. + +Applications that use this protocol are essentially all peers and therefore +nodes the only real difference between Ls and Ls is that a "node" has one or more +listeners running that will, +potentially, allow incoming connections, from other Ls, Ls or Ls + +Any application that is a sink and/or source of data for Ls, is capable of obeying +the protocol message construction rules and understands how to deduplicate incoming messages +correctly can operate as a routeable entity in this protocol. It is called an L. + +An L is called a L if it accepts connections from Ls and is +prepared to route messages on their behalf to other Ls or L. In addition it +may provide some other, usually simpler, interface (eg simple telnet access) for direct user access. + +The concept of an L has been invented because modern clients are +capable of being intelligent than simple +character based connections such as telnet or ax25. They wish to be able to +distinguish between the various classes of message, such as: DX spots, +announces, talk, logging info etc. It is a pain to have to do it, as now, +by trying to make sense of the (slightly different for each piece of node +software) human readable "user" version of the output. Far better to pass on +regular, specified, easily computer decodable versions of the message, +i.e. in this protocol, and leave +the human presentation to the application implementing the L. + +It also helps to modularise the various interfaces that may be implemented such +as the legacy, character based connections of existing PC protocol based nodes. +They should be treated +as local clients, in fact as Ls, B as peers in this protocol. It is likely that, in order +to do this, some extra Ls will need to be defined at application level. + +=head1 Connection Types + +=head2 User + +A L is a connection to a L (that allows such connections) +that does not occur in protocol. All Ls shall be identified with a name +of up to 12 characters in the set [-0-9A-Z_]. All messages have to be routed via the +L to which this L is connected. + +=head2 Endpoint + +An L is a connection to a L that uses the protocol. From a routing point of +view, it is indistiguishable from a L. The L is responsible for creating and decoding +well formed protocol messages. An L does not route beyond the immediate L(s) to +which it is connected. It may also be a L connected to a L which provides some +addressable service that can be queried. + +=head2 Node + +A L is connected to other Ls. It is responsible for routing messages in protocol +from other Ls or Ls, whether directly connected or not. Optionally, a L +may provide other interfaces, such as direct L connections or legacy PC protocol speaking +DX Clusters. + =head1 Routing Section The application that implements this protocol is essentially a line @@ -80,24 +142,29 @@ AX25. Having said that: in context, L in this protocol could be multi/broadcast, either "as is" or wrapped in some other framing protocol. -Because this is an unreliable, best effort, "please route my packets -through your node" protocol, there is no guarantee that a message +Although the physical transport between Ls is reliable, the actual message +is unreliable, because this is an unreliable, best effort, "please route my packets +through your node" protocol. There is no guarantee that a message will get to the other side of a mesh of nodes. There may be a discontinuity either caused by outage or deliberate filtering. However, as it is envisaged that most L will be flood routed or, -in the case of directed L (those that have L and/or +in the case of directed L (those that have L and/or L fields) down some/most/all interfaces showing a route for that direction, it is unlikely that L will be lost in practice. +Assuming that there is a path between all the Ls in a network, then it is guaranteed +that a message will be delivered everywhere, eventually. It is possible (indeed likely) that +copies of a message +will arrive at Ls more than once. Ls are responsible for deduplicating those messages +using the information in the L. + =head2 Field Description -Only the first three fields in the L are compulsory -and indicate that this is a broadcast to be sent to all nodes coming -from the L. If the message needs to be identified as coming -from a user on a node, then the L field is added. +The first four fields in the L are compulsory. However, +a client connection can -Adding a L and/or L field will restrict the destinations +Adding a L and/or L field will restrict the destinations or recipients that receive this message. The L field is incremented on receipt of a message on a node. @@ -120,11 +187,37 @@ More detailed descriptions of the fields follow: =item B This is a compulsory field. It is the name of the originating node. -The field can contain up to 12 characters in the set [-A-Z0-9_] in +The field can contain up to 12 characters in the set [-A-Z0-9_/] in any order. Higher layers may restrict this further. The field must not be changed by any other node. +=item B + +This is the Group (or Channel) to be used for this data. It is compulsory. There +is always a L + +It is a string of up to 12 characters +in the set [-A-Z0-9_] in any order. Optionally, for extra routing to +a specific end point (node or user), it may have another 12 character +field in the same set, concatenated with the string, separated by a ':' +character. + +This field is used either to indicate particular node destination +or to differentiate this broadcast in some way by making this +message as a member of a L. Any message can be sent +down any L. The names of Ls and their usage +is entirely up to the implementor. + +It is assumed that node names can be differentiated from user +names and L names. + +If the field is set to a particular node destination, it will +be routed (rather than broadcast) to that node. However, any +intervening nodes are free to duplicate the message and send +it down more than one, likely looking, interface - depending on any +network policies that may pertain. + =item B This is a compulsory field. It is a 10 hexadecimal digit string which @@ -158,76 +251,10 @@ Implementations may have an upper limit to this field and may silently drop incoming L with a L count greater than the limit. -=item B - -This field is optional. It is the identifier of the originating -user. If it is missing then the message is -assumed to come from the originating node itself. - -It can consist of up to 12 characters in the set [-A-Z0-9_] -in any order. Higher layers may restrict this further. - -=item B - -This field is optional. It is a string of up to 12 characters -in the set [-A-Z0-9_] in any order. - -This field is used either to indicate particular node destination -or to differentiate this broadcast in some way by making this -message as a member of a L. Any message can be sent -down any L. The names of Ls and their usage -is entirely up to the implementor. -It is assumed that node names can be differentiated from user -names and L names. - -If the field is set to a particular node destination, it will -be routed (rather than broadcast) to that node. However, any -intervening nodes are free to duplicate the message and send -it down more than one, likely looking, interface - depending on any -network policies that may pertain. - -=item B - -This field is optional. It is a string of up to 12 characters -in the set [-A-Z0-9_] in any order. Higher layers may restrict -this further. - -Conventionally this field is used to indicate the user to whom -this message is directed. In an ideal world the L field -will be set, by the originating node, to the identifier of the node -on which this user resides. - -If the L field is not set then this message will be -broadcast. However, should a node become apparent (on route) -then nodes are free to fill in the L field and proceed -with a more directed approach. - -If it becomes apparent (on route) that there may be more than -one possible L destination for a L then a node -may duplicate the message (keeping the same L) and -route it onwards. Because of the L inherent in -the system, it is indeterminate as to which destination will -receive the message. It is possible for all or just some -destinations to receive the message. The tuple (L, -L) will determine uniqueness. - -This field can, in the case where L -is set to the name of a node, be set to a L. If this -is the case then this will cause this message to be sent to -a L on the L node only. =back -=head2 Channel - -Channels are a concept very similar to that on IRC. It is a -way of segregating data flows in a network. In principle, subject -to local policy or application requirements, any data (or -L) can be sent down any channel. - -It is up to the implementation whether to use this feature or not. - =head2 Routing It is assumed that nodes will be connected in a looped network with @@ -273,35 +300,32 @@ duplicated! =head2 Examples # on link startup from GB7BAA (both sides hello) - GB7TLH,3D02350001,0,GB7BAA|HELLO,Aranea,1.2,24.123 - GB7BAA,3D02355421,1,GB7TLH|HELLO,Aranea,1.1,23.245 + GB7TLH,ROUTE,3D02350001,0|HELLO,Aranea,1.2,24.123 + GB7BAA,ROUTE,3D02355421,1|HELLO,Aranea,1.1,23.245 # on user startup to GB7TLH - GB7TLH,3D042506F2,0,G1TLH|HELLO,PClient,1.3 + GB7TLH,ROUTE,3D042506F2,0,G1TLH|HELLO,PClient,1.3 # on user disconnection - GB7TLH,3D9534F32D,0,G1TLH|BYE + GB7TLH,ROUTE,3D9534F32D,0,G1TLH|BYE # a talk (actually 'text') message to a user (some distance away # from the origin node) - GB7TLH,3D03450019,3,G1TLH,GB7BAA,G8TIC|T,Hiya Mike what's happening? + GB7TLH,G8TIC,3D03450019,3|T,G1TLH,Hiya Mike what's happening? - # a talk/chat/text message to a channel or group - GB7TLH,0413525F23,2,G1TLH,VHF|T,2m is opening on MS + # a talk/chat/text message to a Group + GB7TLH,VHF,0413525F23,2|T,G1TLH,2m is opening on MS # a ping to find the whereabouts and distance of a user from a node # the hex number on the end is the ping ID - GB7TLH,1512346543,0,,,G7BRN|PING,9F4D - - # the same from a user on GB7TLH - GB7TLH,1512346543,0,G1TLH,,G7BRN|PING,23 + GB7TLH,G7BRN,1512346543,0|PING,G1TLH,9F4D # this effectively asks whether the user is on-line on a particular node - GB7TLH,1512346543,0,G1TLH,GB7DJK,G7BRN|PING,35DE + GB7TLH,GB7BAA:G7BRN,1512346543,0|PING,G1TLH,35DE # A possible reply, same ID as ping followed by the no of hops on the - # ping that was received - GB7DJK,1512450534,3,G7BRN,GB7TLH,G1TLH|PONG,35DE,3 + # ping that was received thus telling you how far away it is. + GB7BAA,G1TLH,1512450534,3|PONG,G7BRN,35DE,3 =head1 Command Section @@ -341,7 +365,7 @@ vertical bar '|', percent '%', equals '=' and non printable characters less than 127 (or %7F in hex) -[including newline and carraige return] are tranlated to +[including newline and carraige return] are translated to their two hex digit equivalent preceeded by the percent '%' character. For example: @@ -414,7 +438,7 @@ disconnected. =item B - PING, + PING,, Command to send a ping to a node or user. This command is used both by the software and users to determine a) whether a node or user exists and b) how good the path is @@ -426,7 +450,7 @@ will identify this ping using the tuple (L,) as unique. =item B - PONG,, + PONG,,, Command to reply to a ping. This is sent as a reply to an incoming ping command. The is the one supplied and the is the number of @@ -447,7 +471,7 @@ Dirk Koopman, G1TLH, Edjk@tobit.co.ukE =head1 COPYRIGHT AND LICENSE -Copyright 2004 by Dirk Koopman, G1TLH +Copyright 2004-2005 by Dirk Koopman, G1TLH This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.