view Documentation/networking/wan-router.txt @ 897:329ea0ccb344

balloon: try harder to balloon up under memory pressure.

Currently if the balloon driver is unable to increase the guest's
reservation it assumes the failure was due to reaching its full
allocation, gives up on the ballooning operation and records the limit
it reached as the "hard limit". The driver will not try again until
the target is set again (even to the same value).

However it is possible that ballooning has in fact failed due to
memory pressure in the host and therefore it is desirable to keep
attempting to reach the target in case memory becomes available. The
most likely scenario is that some guests are ballooning down while
others are ballooning up and therefore there is temporary memory
pressure while things stabilise. You would not expect a well behaved
toolstack to ask a domain to balloon to more than its allocation nor
would you expect it to deliberately over-commit memory by setting
balloon targets which exceed the total host memory.

This patch drops the concept of a hard limit and causes the balloon
driver to retry increasing the reservation on a timer in the same
manner as when decreasing the reservation.

Also if we partially succeed in increasing the reservation
(i.e. receive less pages than we asked for) then we may as well keep
those pages rather than returning them to Xen.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Fri Jun 05 14:01:20 2009 +0100 (2009-06-05)
parents 831230e53067
line source
1 ------------------------------------------------------------------------------
2 Linux WAN Router Utilities Package
3 ------------------------------------------------------------------------------
4 Version 2.2.1
5 Mar 28, 2001
6 Author: Nenad Corbic <ncorbic@sangoma.com>
7 Copyright (c) 1995-2001 Sangoma Technologies Inc.
8 ------------------------------------------------------------------------------
12 Wide Area Networks (WANs) are used to interconnect Local Area Networks (LANs)
13 and/or stand-alone hosts over vast distances with data transfer rates
14 significantly higher than those achievable with commonly used dial-up
15 connections.
17 Usually an external device called `WAN router' sitting on your local network
18 or connected to your machine's serial port provides physical connection to
19 WAN. Although router's job may be as simple as taking your local network
20 traffic, converting it to WAN format and piping it through the WAN link, these
21 devices are notoriously expensive, with prices as much as 2 - 5 times higher
22 then the price of a typical PC box.
24 Alternatively, considering robustness and multitasking capabilities of Linux,
25 an internal router can be built (most routers use some sort of stripped down
26 Unix-like operating system anyway). With a number of relatively inexpensive WAN
27 interface cards available on the market, a perfectly usable router can be
28 built for less than half a price of an external router. Yet a Linux box
29 acting as a router can still be used for other purposes, such as fire-walling,
30 running FTP, WWW or DNS server, etc.
32 This kernel module introduces the notion of a WAN Link Driver (WLD) to Linux
33 operating system and provides generic hardware-independent services for such
34 drivers. Why can existing Linux network device interface not be used for
35 this purpose? Well, it can. However, there are a few key differences between
36 a typical network interface (e.g. Ethernet) and a WAN link.
38 Many WAN protocols, such as X.25 and frame relay, allow for multiple logical
39 connections (known as `virtual circuits' in X.25 terminology) over a single
40 physical link. Each such virtual circuit may (and almost always does) lead
41 to a different geographical location and, therefore, different network. As a
42 result, it is the virtual circuit, not the physical link, that represents a
43 route and, therefore, a network interface in Linux terms.
45 To further complicate things, virtual circuits are usually volatile in nature
46 (excluding so called `permanent' virtual circuits or PVCs). With almost no
47 time required to set up and tear down a virtual circuit, it is highly desirable
48 to implement on-demand connections in order to minimize network charges. So
49 unlike a typical network driver, the WAN driver must be able to handle multiple
50 network interfaces and cope as multiple virtual circuits come into existence
51 and go away dynamically.
53 Last, but not least, WAN configuration is much more complex than that of say
54 Ethernet and may well amount to several dozens of parameters. Some of them
55 are "link-wide" while others are virtual circuit-specific. The same holds
56 true for WAN statistics which is by far more extensive and extremely useful
57 when troubleshooting WAN connections. Extending the ifconfig utility to suit
58 these needs may be possible, but does not seem quite reasonable. Therefore, a
59 WAN configuration utility and corresponding application programmer's interface
60 is needed for this purpose.
62 Most of these problems are taken care of by this module. Its goal is to
63 provide a user with more-or-less standard look and feel for all WAN devices and
64 assist a WAN device driver writer by providing common services, such as:
66 o User-level interface via /proc file system
67 o Centralized configuration
68 o Device management (setup, shutdown, etc.)
69 o Network interface management (dynamic creation/destruction)
70 o Protocol encapsulation/decapsulation
72 To ba able to use the Linux WAN Router you will also need a WAN Tools package
73 available from
75 ftp.sangoma.com/pub/linux/current_wanpipe/wanpipe-X.Y.Z.tgz
77 where vX.Y.Z represent the wanpipe version number.
79 For technical questions and/or comments please e-mail to ncorbic@sangoma.com.
80 For general inquiries please contact Sangoma Technologies Inc. by
82 Hotline: 1-800-388-2475 (USA and Canada, toll free)
83 Phone: (905) 474-1990 ext: 106
84 Fax: (905) 474-9223
85 E-mail: dm@sangoma.com (David Mandelstam)
86 WWW: http://www.sangoma.com
91 Please read the WanpipeForLinux.pdf manual on how to
92 install the WANPIPE tools and drivers properly.
95 After installing wanpipe package: /usr/local/wanrouter/doc.
96 On the ftp.sangoma.com : /linux/current_wanpipe/doc
101 This program is free software; you can redistribute it and/or modify it under
102 the terms of the GNU General Public License as published by the Free Software
103 Foundation; either version 2, or (at your option) any later version.
105 This program is distributed in the hope that it will be useful, but WITHOUT
106 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
107 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
109 You should have received a copy of the GNU General Public License along with
110 this program; if not, write to the Free Software Foundation, Inc., 675 Mass
111 Ave, Cambridge, MA 02139, USA.
117 This product is based on the WANPIPE(tm) Multiprotocol WAN Router developed
118 by Sangoma Technologies Inc. for Linux 2.0.x and 2.2.x. Success of the WANPIPE
119 together with the next major release of Linux kernel in summer 1996 commanded
120 adequate changes to the WANPIPE code to take full advantage of new Linux
121 features.
123 Instead of continuing developing proprietary interface tied to Sangoma WAN
124 cards, we decided to separate all hardware-independent code into a separate
125 module and defined two levels of interfaces - one for user-level applications
126 and another for kernel-level WAN drivers. WANPIPE is now implemented as a
127 WAN driver compliant with the WAN Link Driver interface. Also a general
128 purpose WAN configuration utility and a set of shell scripts was developed to
129 support WAN router at the user level.
131 Many useful ideas concerning hardware-independent interface implementation
132 were given by Mike McLagan <mike.mclagan@linux.org> and his implementation
133 of the Frame Relay router and drivers for Sangoma cards (dlci/sdla).
135 With the new implementation of the APIs being incorporated into the WANPIPE,
136 a special thank goes to Alan Cox in providing insight into BSD sockets.
138 Special thanks to all the WANPIPE users who performed field-testing, reported
139 bugs and made valuable comments and suggestions that help us to improve this
140 product.
146 o Updated the WANCFG utility
147 Calls the pppconfig to configure the PPPD
148 for async connections.
150 o Added the PPPCONFIG utility
151 Used to configure the PPPD dameon for the
152 WANPIPE Async PPP and standard serial port.
153 The wancfg calls the pppconfig to configure
154 the pppd.
156 o Fixed the PCI autodetect feature.
157 The SLOT 0 was used as an autodetect option
158 however, some high end PC's slot numbers start
159 from 0.
161 o This release has been tested with the new backupd
162 daemon release.
167 /etc: (or user defined)
168 wanpipe1.conf default router configuration file
170 /lib/modules/X.Y.Z/misc:
171 wanrouter.o router kernel loadable module
172 af_wanpipe.o wanpipe api socket module
174 /lib/modules/X.Y.Z/net:
175 sdladrv.o Sangoma SDLA support module
176 wanpipe.o Sangoma WANPIPE(tm) driver module
178 /proc/net/wanrouter
179 Config reads current router configuration
180 Status reads current router status
181 {name} reads WAN driver statistics
183 /usr/sbin:
184 wanrouter wanrouter start-up script
185 wanconfig wanrouter configuration utility
186 sdladump WANPIPE adapter memory dump utility
187 fpipemon Monitor for Frame Relay
188 cpipemon Monitor for Cisco HDLC
189 ppipemon Monitor for PPP
190 xpipemon Monitor for X25
191 wpkbdmon WANPIPE keyboard led monitor/debugger
193 /usr/local/wanrouter:
194 README this file
195 COPYING GNU General Public License
196 Setup installation script
197 Filelist distribution definition file
198 wanrouter.rc meta-configuration file
199 (used by the Setup and wanrouter script)
201 /usr/local/wanrouter/doc:
202 wanpipeForLinux.pdf WAN Router User's Manual
204 /usr/local/wanrouter/patches:
205 wanrouter-v2213.gz patch for Linux kernels 2.2.11 up to 2.2.13.
206 wanrouter-v2214.gz patch for Linux kernel 2.2.14.
207 wanrouter-v2215.gz patch for Linux kernels 2.2.15 to 2.2.17.
208 wanrouter-v2218.gz patch for Linux kernels 2.2.18 and up.
209 wanrouter-v240.gz patch for Linux kernel 2.4.0.
210 wanrouter-v242.gz patch for Linux kernel 2.4.2 and up.
211 wanrouter-v2034.gz patch for Linux kernel 2.0.34
212 wanrouter-v2036.gz patch for Linux kernel 2.0.36 and up.
214 /usr/local/wanrouter/patches/kdrivers:
215 Sources of the latest WANPIPE device drivers.
216 These are used to UPGRADE the linux kernel to the newest
217 version if the kernel source has already been pathced with
218 WANPIPE drivers.
220 /usr/local/wanrouter/samples:
221 interface sample interface configuration file
222 wanpipe1.cpri CHDLC primary port
223 wanpipe2.csec CHDLC secondary port
224 wanpipe1.fr Frame Relay protocol
225 wanpipe1.ppp PPP protocol )
226 wanpipe1.asy CHDLC ASYNC protocol
227 wanpipe1.x25 X25 protocol
228 wanpipe1.stty Sync TTY driver (Used by Kernel PPPD daemon)
229 wanpipe1.atty Async TTY driver (Used by Kernel PPPD daemon)
230 wanrouter.rc sample meta-configuration file
232 /usr/local/wanrouter/util:
233 * wan-tools utilities source code
235 /usr/local/wanrouter/api/x25:
236 * x25 api sample programs.
237 /usr/local/wanrouter/api/chdlc:
238 * chdlc api sample programs.
239 /usr/local/wanrouter/api/fr:
240 * fr api sample programs.
241 /usr/local/wanrouter/config/wancfg:
242 wancfg WANPIPE GUI configuration program.
243 Creates wanpipe#.conf files.
244 /usr/local/wanrouter/config/cfgft1:
245 cfgft1 GUI CSU/DSU configuration program.
247 /usr/include/linux:
248 wanrouter.h router API definitions
249 wanpipe.h WANPIPE API definitions
250 sdladrv.h SDLA support module API definitions
251 sdlasfm.h SDLA firmware module definitions
252 if_wanpipe.h WANPIPE Socket definitions
253 if_wanpipe_common.h WANPIPE Socket/Driver common definitions.
254 sdlapci.h WANPIPE PCI definitions
257 /usr/src/linux/net/wanrouter:
258 * wanrouter source code
260 /var/log:
261 wanrouter wanrouter start-up log (created by the Setup script)
263 /var/lock: (or /var/lock/subsys for RedHat)
264 wanrouter wanrouter lock file (created by the Setup script)
266 /usr/local/wanrouter/firmware:
267 fr514.sfm Frame relay firmware for Sangoma S508/S514 card
268 cdual514.sfm Dual Port Cisco HDLC firmware for Sangoma S508/S514 card
269 ppp514.sfm PPP Firmware for Sangoma S508 and S514 cards
270 x25_508.sfm X25 Firmware for Sangoma S508 card.
275 1.0.0 December 31, 1996 Initial version
277 1.0.1 January 30, 1997 Status and statistics can be read via /proc
278 filesystem entries.
280 1.0.2 April 30, 1997 Added UDP management via monitors.
282 1.0.3 June 3, 1997 UDP management for multiple boards using Frame
283 Relay and PPP
284 Enabled continuous transmission of Configure
285 Request Packet for PPP (for 508 only)
286 Connection Timeout for PPP changed from 900 to 0
287 Flow Control Problem fixed for Frame Relay
289 1.0.4 July 10, 1997 S508/FT1 monitoring capability in fpipemon and
290 ppipemon utilities.
291 Configurable TTL for UDP packets.
292 Multicast and Broadcast IP source addresses are
293 silently discarded.
295 1.0.5 July 28, 1997 Configurable T391,T392,N391,N392,N393 for Frame
296 Relay in router.conf.
297 Configurable Memory Address through router.conf
298 for Frame Relay, PPP and X.25. (commenting this
299 out enables auto-detection).
300 Fixed freeing up received buffers using kfree()
301 for Frame Relay and X.25.
302 Protect sdla_peek() by calling save_flags(),
303 cli() and restore_flags().
304 Changed number of Trace elements from 32 to 20
305 Added DLCI specific data monitoring in FPIPEMON.
306 2.0.0 Nov 07, 1997 Implemented protection of RACE conditions by
307 critical flags for FRAME RELAY and PPP.
308 DLCI List interrupt mode implemented.
309 IPX support in FRAME RELAY and PPP.
310 IPX Server Support (MARS)
311 More driver specific stats included in FPIPEMON
312 and PIPEMON.
314 2.0.1 Nov 28, 1997 Bug Fixes for version 2.0.0.
315 Protection of "enable_irq()" while
316 "disable_irq()" has been enabled from any other
317 routine (for Frame Relay, PPP and X25).
318 Added additional Stats for Fpipemon and Ppipemon
319 Improved Load Sharing for multiple boards
321 2.0.2 Dec 09, 1997 Support for PAP and CHAP for ppp has been
322 implemented.
324 2.0.3 Aug 15, 1998 New release supporting Cisco HDLC, CIR for Frame
325 relay, Dynamic IP assignment for PPP and Inverse
326 Arp support for Frame-relay. Man Pages are
327 included for better support and a new utility
328 for configuring FT1 cards.
330 2.0.4 Dec 09, 1998 Dual Port support for Cisco HDLC.
331 Support for HDLC (LAPB) API.
332 Supports BiSync Streaming code for S502E
333 and S503 cards.
334 Support for Streaming HDLC API.
335 Provides a BSD socket interface for
336 creating applications using BiSync
337 streaming.
339 2.0.5 Aug 04, 1999 CHDLC initializatin bug fix.
340 PPP interrupt driven driver:
341 Fix to the PPP line hangup problem.
342 New PPP firmware
343 Added comments to the startup SYSTEM ERROR messages
344 Xpipemon debugging application for the X25 protocol
345 New USER_MANUAL.txt
346 Fixed the odd boundary 4byte writes to the board.
347 BiSync Streaming code has been taken out.
348 Available as a patch.
349 Streaming HDLC API has been taken out.
350 Available as a patch.
352 2.0.6 Aug 17, 1999 Increased debugging in statup scripts
353 Fixed insallation bugs from 2.0.5
354 Kernel patch works for both 2.2.10 and 2.2.11 kernels.
355 There is no functional difference between the two packages
357 2.0.7 Aug 26, 1999 o Merged X25API code into WANPIPE.
358 o Fixed a memory leak for X25API
359 o Updated the X25API code for 2.2.X kernels.
360 o Improved NEM handling.
362 2.1.0 Oct 25, 1999 o New code for S514 PCI Card
363 o New CHDLC and Frame Relay drivers
364 o PPP and X25 are not supported in this release
366 2.1.1 Nov 30, 1999 o PPP support for S514 PCI Cards
368 2.1.3 Apr 06, 2000 o Socket based x25api
369 o Socket based chdlc api
370 o Socket based fr api
371 o Dual Port Receive only CHDLC support.
372 o Asynchronous CHDLC support (Secondary Port)
373 o cfgft1 GUI csu/dsu configurator
374 o wancfg GUI configuration file
375 configurator.
376 o Architectual directory changes.
378 beta-2.1.4 Jul 2000 o Dynamic interface configuration:
379 Network interfaces reflect the state
380 of protocol layer. If the protocol becomes
381 disconnected, driver will bring down
382 the interface. Once the protocol reconnects
383 the interface will be brought up.
385 Note: This option is turned off by default.
387 o Dynamic wanrouter setup using 'wanconfig':
388 wanconfig utility can be used to
389 shutdown,restart,start or reconfigure
390 a virtual circuit dynamically.
392 Frame Relay: Each DLCI can be:
393 created,stopped,restarted and reconfigured
394 dynamically using wanconfig.
396 ex: wanconfig card wanpipe1 dev wp1_fr16 up
398 o Wanrouter startup via command line arguments:
399 wanconfig also supports wanrouter startup via command line
400 arguments. Thus, there is no need to create a wanpipe#.conf
401 configuration file.
403 o Socket based x25api update/bug fixes.
404 Added support for LCN numbers greater than 255.
405 Option to pass up modem messages.
406 Provided a PCI IRQ check, so a single S514
407 card is guaranteed to have a non-sharing interrupt.
409 o Fixes to the wancfg utility.
410 o New FT1 debugging support via *pipemon utilities.
411 o Frame Relay ARP support Enabled.
413 beta3-2.1.4 Jul 2000 o X25 M_BIT Problem fix.
414 o Added the Multi-Port PPP
415 Updated utilites for the Multi-Port PPP.
417 2.1.4 Aut 2000
418 o In X25API:
419 Maximum packet an application can send
420 to the driver has been extended to 4096 bytes.
422 Fixed the x25 startup bug. Enable
423 communications only after all interfaces
424 come up. HIGH SVC/PVC is used to calculate
425 the number of channels.
426 Enable protocol only after all interfaces
427 are enabled.
429 o Added an extra state to the FT1 config, kernel module.
430 o Updated the pipemon debuggers.
432 o Blocked the Multi-Port PPP from running on kernels
433 2.2.16 or greater, due to syncppp kernel module
434 change.
436 beta1-2.1.5 Nov 15 2000
437 o Fixed the MulitPort PPP Support for kernels 2.2.16 and above.
438 2.2.X kernels only
440 o Secured the driver UDP debugging calls
441 - All illegal netowrk debugging calls are reported to
442 the log.
443 - Defined a set of allowed commands, all other denied.
445 o Cpipemon
446 - Added set FT1 commands to the cpipemon. Thus CSU/DSU
447 configuraiton can be performed using cpipemon.
448 All systems that cannot run cfgft1 GUI utility should
449 use cpipemon to configure the on board CSU/DSU.
452 o Keyboard Led Monitor/Debugger
453 - A new utilty /usr/sbin/wpkbdmon uses keyboard leds
454 to convey operatinal statistic information of the
455 Sangoma WANPIPE cards.
456 NUM_LOCK = Line State (On=connected, Off=disconnected)
457 CAPS_LOCK = Tx data (On=transmitting, Off=no tx data)
458 SCROLL_LOCK = Rx data (On=receiving, Off=no rx data
460 o Hardware probe on module load and dynamic device allocation
461 - During WANPIPE module load, all Sangoma cards are probed
462 and found information is printed in the /var/log/messages.
463 - If no cards are found, the module load fails.
464 - Appropriate number of devices are dynamically loaded
465 based on the number of Sangoma cards found.
467 Note: The kernel configuraiton option
468 CONFIG_WANPIPE_CARDS has been taken out.
470 o Fixed the Frame Relay and Chdlc network interfaces so they are
471 compatible with libpcap libraries. Meaning, tcpdump, snort,
472 ethereal, and all other packet sniffers and debuggers work on
473 all WANPIPE netowrk interfaces.
474 - Set the network interface encoding type to ARPHRD_PPP.
475 This tell the sniffers that data obtained from the
476 network interface is in pure IP format.
477 Fix for 2.2.X kernels only.
479 o True interface encoding option for Frame Relay and CHDLC
480 - The above fix sets the network interface encoding
481 type to ARPHRD_PPP, however some customers use
482 the encoding interface type to determine the
483 protocol running. Therefore, the TURE ENCODING
484 option will set the interface type back to the
485 original value.
487 NOTE: If this option is used with Frame Relay and CHDLC
488 libpcap library support will be broken.
489 i.e. tcpdump will not work.
490 Fix for 2.2.x Kernels only.
492 o Ethernet Bridgind over Frame Relay
493 - The Frame Relay bridging has been developed by
494 Kristian Hoffmann and Mark Wells.
495 - The Linux kernel bridge is used to send ethernet
496 data over the frame relay links.
497 For 2.2.X Kernels only.
499 o Added extensive 2.0.X support. Most new features of
500 2.1.5 for protocols Frame Relay, PPP and CHDLC are
501 supported under 2.0.X kernels.
503 beta1-2.2.0 Dec 30 2000
504 o Updated drivers for 2.4.X kernels.
505 o Updated drivers for SMP support.
506 o X25API is now able to share PCI interrupts.
507 o Took out a general polling routine that was used
508 only by X25API.
509 o Added appropriate locks to the dynamic reconfiguration
510 code.
511 o Fixed a bug in the keyboard debug monitor.
513 beta2-2.2.0 Jan 8 2001
514 o Patches for 2.4.0 kernel
515 o Patches for 2.2.18 kernel
516 o Minor updates to PPP and CHLDC drivers.
517 Note: No functional difference.
519 beta3-2.2.9 Jan 10 2001
520 o I missed the 2.2.18 kernel patches in beta2-2.2.0
521 release. They are included in this release.
523 Stable Release
524 2.2.0 Feb 01 2001
525 o Bug fix in wancfg GUI configurator.
526 The edit function didn't work properly.
529 bata1-2.2.1 Feb 09 2001
530 o WANPIPE TTY Driver emulation.
531 Two modes of operation Sync and Async.
532 Sync: Using the PPPD daemon, kernel SyncPPP layer
533 and the Wanpipe sync TTY driver: a PPP protocol
534 connection can be established via Sangoma adapter, over
535 a T1 leased line.
537 The 2.4.0 kernel PPP layer supports MULTILINK
538 protocol, that can be used to bundle any number of Sangoma
539 adapters (T1 lines) into one, under a single IP address.
540 Thus, efficiently obtaining multiple T1 throughput.
542 NOTE: The remote side must also implement MULTILINK PPP
543 protocol.
545 Async:Using the PPPD daemon, kernel AsyncPPP layer
546 and the WANPIPE async TTY driver: a PPP protocol
547 connection can be established via Sangoma adapter and
548 a modem, over a telephone line.
550 Thus, the WANPIPE async TTY driver simulates a serial
551 TTY driver that would normally be used to interface the
552 MODEM to the linux kernel.
554 o WANPIPE PPP Backup Utility
555 This utility will monitor the state of the PPP T1 line.
556 In case of failure, a dial up connection will be established
557 via pppd daemon, ether via a serial tty driver (serial port),
558 or a WANPIPE async TTY driver (in case serial port is unavailable).
560 Furthermore, while in dial up mode, the primary PPP T1 link
561 will be monitored for signs of life.
563 If the PPP T1 link comes back to life, the dial up connection
564 will be shutdown and T1 line re-established.
567 o New Setup installation script.
568 Option to UPGRADE device drivers if the kernel source has
569 already been patched with WANPIPE.
571 Option to COMPILE WANPIPE modules against the currently
572 running kernel, thus no need for manual kernel and module
573 re-compilatin.
575 o Updates and Bug Fixes to wancfg utility.
577 bata2-2.2.1 Feb 20 2001
579 o Bug fixes to the CHDLC device drivers.
580 The driver had compilation problems under kernels
581 2.2.14 or lower.
583 o Bug fixes to the Setup installation script.
584 The device drivers compilation options didn't work
585 properly.
587 o Update to the wpbackupd daemon.
588 Optimized the cross-over times, between the primary
589 link and the backup dialup.
591 beta3-2.2.1 Mar 02 2001
592 o Patches for 2.4.2 kernel.
594 o Bug fixes to util/ make files.
595 o Bug fixes to the Setup installation script.
597 o Took out the backupd support and made it into
598 as separate package.
600 beta4-2.2.1 Mar 12 2001
602 o Fix to the Frame Relay Device driver.
603 IPSAC sends a packet of zero length
604 header to the frame relay driver. The
605 driver tries to push its own 2 byte header
606 into the packet, which causes the driver to
607 crash.
609 o Fix the WANPIPE re-configuration code.
610 Bug was found by trying to run the cfgft1 while the
611 interface was already running.
613 o Updates to cfgft1.
614 Writes a wanpipe#.cfgft1 configuration file
615 once the CSU/DSU is configured. This file can
616 holds the current CSU/DSU configuration.
620 >>>>>> END OF README <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<