45 lines
2.1 KiB
Plaintext
45 lines
2.1 KiB
Plaintext
$Id: PROBLEMS-2.1.114,v 1.2 1999/07/01 18:00:25 he Exp $
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Known problems observed when using X.25 on top of isdn with kernels
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===================================================================
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The X.25 PLP implementation was originally designed to be used on top
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of a synchronous line (accessed via an X.25 network device driver)
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or on top of lan (IEEE 802 LLC type 2). Furthermore, the X.25
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implementation as well as the related isdn4linux extensions are labelled
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as "EXPERIMENTAL" code in the kernel source tree. Thus, the X.25 protocol
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sometimes doesn't behave as you would expect, in particular when used
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on top of isdn.
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Problems related to isdn drivers:
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=================================
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The isdnloop HL driver apparently has problems to re-establish a
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connection that has been hung up from the outgoing device. You have to
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unload the isdnloop driver after the faked isdn-connection is closed
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and insmod it again. With the Hisax driver, this problem is not present.
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When ifconfig'ing isdn network interfaces (with encap x25iface set) down,
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"disconnect indication while unconfigured" messages might appear in
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the syslog. This does not indicate any problem and can be ignored.
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When establishing the first X.25 connection on a link, there is a
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delay of some seconds until the link becomes established. This is only
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a performance problem and harmless. Furthermore, this is fixed with
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recent isdn4linux versions from the isdn4linux CVS tree. Kernel
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2.2.10 still contains this outdated isdn4linux version.
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Problems related to the X.25 PLP implementation:
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================================================
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isdn B channels are not closed automatically when the X.25 PLP
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connection is closed. If you are lucky, your peer does it. eftd
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and the eftp.sh shell script also try to close connection. But this
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might sometime fail due to bugs. Thus,
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monitor your isdn connections while using X.25 on top of isdn4linux
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(i.e. by watching syslog messages or by an isdn monitor program).
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You can close the B channel connection by hand (using the
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"isdnctrl hangup" command) or rely on the isdn network interface's
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hangup timeout.
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