_ _:. :$$$$$ _ . - +. :l$³³$$ s¿¿,,_ +:@QSSS$$$$$ `` $$$$$$$$bs¿.`"Ù?$$$l [ Ip->x25 ] 'ÀÀ?$$³$$$$b¿_ . [ Common Kinds of Gateways ] `"À$³$b. . [ Lady ] `À?b. `. [ lady@stsland.ru ] `Ù. + `$ _. ` 1. NSG routers. 2. Telematics ACP. 3. Cisco routers. 4. X.25 over TCP (XOT) 5. 7+ PAD 1. NSG routers. NX-300 - it is intended basically for access in corporate lans. Has 2 universal wan port (sync/async) also supports many protocols, as Example: For asynchronous lines: ú Frame Relay ú X.25 (X.25 DTE/Switch DCE, RFC 1356, Reverse Charging, Fast Select, NUI); ú Cisco/HDLC. For synchronous: ú PPP (RFC-1661, RFC-1662); ú SLIP (RFC-1055); ú PAD (X.3/X.28/X.29). NSG-504 - as a whole too most, but it was positioned for work with DSL. Also used for access in x25 and Frame Relay. Have the same set of protocols as in NS-300. Standard prompt of NX-300 and NSG-5xx mostly "*" (like in usual pads), Though there is also something such as " nx300 > ". Such pads works is rather transparent: the data acting from the user will be transformed in x25 packets according to adjustments of this pad, and transferred via x25. And vice-versa. Pads have standard x28 commands, but this also have some additional: - cut-- *id NSG PAD Version 7.6.1 (Mar 1 2002) PORT *TN00 ADn - a call of a auto substitutions line, where n number of a line (from 0 up to 7) MN - Manager (setup): *mn COM Password: To prevent illegal access to Manager change the password (see ' S W PW:? ') You have messages. Type command D E (Display Errors) nx-300: - cut-- On default,the password to Manager empty.Some interesting info in adjustments: D A - display address table (' S A? ' for more); D R - display X25 routes and PVC (' S R? ' for more); D U - display NUI (' D U ' command shows passwords of PAD users); D W - display system parameters (' S W? ' for more); etc. You may use such pads, as well as any others, for exception of that codes of mistakes are given slightly in the other kind: - cut-- *25017720083334 COM Solstice X.29 Terminal Service login: *25017720083335 CLR DTE C:0 D:0 - (here - Call cleared by remote device). - cut-- 2. Telematics ACP. ACP (Access Communication Processor) - the switchboards used for accessing in x25 nets. With the help of such switchboards many x25 networks was constructed, for example such as Rosnet (2506), ItalPac (2222) etc. Standard ACP prompt: - cut-- ACP gateway 50; port: t051 date: 2003-10-10 time: 3:53:09 * - cut-- Also setup callback is possible: - cut-- Class of Service? techpub User name? john We wait when ACP will call us (about 1 minute) Password? 1234 ACP gateway 1000; port: 13 The system will go down at midnight. You are not allowed to make reverse charging calls today. * - cut-- Needed mention, that on such ACP we may look at pad mnemonics list: - cut-- *help mnemonics sym = " 50 * "sym" trace = " 50 * "trace" ACP10 = " 1010 * "sym" HOSTESS = "23421112234563" PSSCLOCK = "23421920100605" ACP550 = " 1055 * "sym" - cut-- Here, for example, it is visible, where pad is located (England (2342)). "sym" - it is bindings to system manager: 50 is the address and ` sym is the call user data. The asterisk delimits the address from the call user data. - cut- *sym ACP:fac: p (128,128), w (2,2), d (9600,9600) com identification: <-pass system manager Copyright (c) 2000 NetKit Solutions LLC all rights reserved BTACP50 sym > The configuration is original, but rather simple.Yet a lot of interesting files on it, "show file" will help with it. Small list: acctoper - Accounting configuration. nodeconf - Global system (node) configuration. frvcconf - Frame relay PVC configuration. linkconf - Defines the behavior of the X.25 link (frame) level. linkstat - X.25 link (frame) statistics. x25stat - X.25 packet level status/statistics. x25call - X.25 interface call status. Example, working with files: - cut-- BTACP50 sym > file netmap record initialized to default values BTACP50 sym > lnames file netmap contains the following records: 1. 0* 2. 50* 3. * 4. 50* 5. * 6. 123435099351* 7. 999 8. 1010* 9. 23421113323410* 10. 23421113323455* 11. 1055* 12. 888 13. 7* 14. 555 15. 234 16. 23421230223503 17. 2342911* BTACP50 sym > list 16 file netmap contains the following records: record *16 dynamic parameters 0. netaddr = 23421230223503 1. userdata = * 2. nodeid = 432 - cut-- 3. Cisco routers. Ios has support of x25 nets. ITU-T recommendations implemented, that allow use this routers for accessing PSN, and may give x25 services, what often used by banks, government and corporations. The router configuration in relation to x25 allows to do such things as: - choice encapsulation of X.25 packets in DTE or DCE mode; - translation (IP, IPX etc.) addresses in X.121 addresses; - the organization of permanent virtual connections (PVC) X.25; - the organization incoming, outgoing or bi-directional switched virtual connections (SVC) X.25; - Adjustment parameters of X.25: lengths of incoming and outgoing packets, windows sizes of reception and distribution of packets, a range of numbering of packets on the third Level; - organization of PADs ports according to recommendations X.3/X.28/X.29. Cisco`s system u may found everywhere . For us interesting, exist or not route in x25: cisco-1 > sh x25 route %X.25 routing is not enabled cisco-2 > sh x25 route Number X.121 CUD Forward To 1 91822065 translation, 64 uses 2 918220650 translation, 0 uses cisco-3 > sh x25 route * Match Substitute Route to 1 dest 111 xot 10.10.10.1 Here accordingly: cisco-1 - has no relation to x25 except IOS has X.25 software.;) cisco-2 - connected to x25 network directly. cisco-3 - connected to x25 through another cisco XOT. Well that's all, now it is work;): cisco-3 > pad 25017720083335 Trying 25017720083335. Open Well or cisco-3 > x28 *25017720083335 COM etc... Also cisco pad can be already bind on separate port. Prompt as well as at nx-300, nsg-5xx: "*". Help format slightly different from another, it allow fast determine that it cisco pad. - cut-- *help The "help" PAD command signal consists of the following elements: < help PAD command signal > < help subject > where < help subject > is the identifier for the type of explanatory information requested - cut-- Or so: - cut-- *help CALL [?] | [[address] [*P |*D |*Fuser data]] CLR [fast select user data] HALF [*] | [[-] ch1, ch2..., chn] ---blablalba--- SET? [ref1:val1 [, ref2:val2..., refn:valn]] TABS {LCL tab_num} {REM tab_num} {EXP exp_num} - cut-- 5. X.25 over TCP (XOT) Now a bit about encapsulation. For tutorial info read "Cisco Systems X.25 over TCP (XOT)" (rfc1613). In brief, main idea that x25 packets transferred via tcp :) For that purpose was reserved 1998 port. Protocol was developed directly cisco and JANET. In what his interest? Xot protocol implemented in all upper described hardware (NX-300, NSG-5xx, ACP, cisco). If you want it is possible to find xot with routines in different x25 networks and to make the gateway in x25. In other words, setup x25 route from one route, through xot of another. telnet xot We--------> cisco1-----> cisco2 (xot)----> x25 On cisco1 we build up routines through cisco2`s xot port, which have route in x25.Well that's all :) For comfortable,it is possible bind x28 pad on separate port. All about it well described on cisco.com so trying ;). 6. 7 + PAD Information about this pad it is not enough in internet. You may possible find it on hardware by Hungarian 7 + Computer Network Ltd. I however get soft from this hardware (yet many interesting things),but connect to global x25 not have successful, may be only local network. Search and will find :) ---cut--- 7 + PAD v3.33 Tpad0 *help PROF=4 PROF [?] [n]; HELP; CLS; STAT [US]; CLOSE SET [?] [par:val [, par:val..]]; PAR [?] [par:val [, par:val..]] WAIT nsec [cmd]; IDOFF; DO cmdfn; [Nnui] [, R] [, Trpoa] [, Ggg] [, C] [-] [adr] [Dudta] *m COM Connected to MON 0 *** ARPI (10 7 + MONITOR *** Ver: 4.91 Rev: 44 Start at: Wed Jun 25 09:36:47 2003 UPTIME: 13 day (s), 4 hour (s), 3 minute (s) * help ? address bye connection decimal diagnostic dlci echo emitter getfile hexadecimal interrupt mer nop octal phone repeat reset rselect sdce single sink smonitor spsize status swindow sysinfo umonitor *031069 CLR DER C:9 D:0 *smonitor (system monitor?) Password: (new commands in the menu) * ---cut--- nua format: n555560intranet-.router Some nui of this network: 557001 sport 557010 balazs 557015 mgintner 557005 idravai Also exists various gates like Compuserve, UUNET, SOVAMNET, and others, but no sense to present them. At the last words, if you want determine nua of gate, you may connect to nua what show calling nua, or use commands from cisco console like sh x25 pad, sh x25 etc.. cisco_exec > sh x25 pad - blablabla-- SVC 1, State: D1, Interface: Serial0 Started 00:00:18, last input 00:00:00, output 00:00:00 Connects 025017720656621 <-> PAD <---our nua - blablabla-- cisco_exec > sh x25 vc SVC 1, State: D1, Interface: Serial0 Started 00:00:35, last input 00:00:00, output 00:00:00 Connects 025017720656621 <-> PAD <---our nua - blablabla-- Well that's all, what i wanted to tell. Successful searches;) As addon for article, bonus have some nuas from different x25 networks. For expansion of you look :) references: [1] Service X.25 on the basis of routers // Computer press - 12/98 [2] A transport subsystem of non-uniform networks // Victor and Natalia Olifer [3] Multilegal routers and switchboards of packages NPS.7e, NSG.500, NX.300, NSG.800 // the Part 7 - Switching and services X.25 [4] ACP configuration file summary [5] ACP installation manual