<p class="MsoNormal"><span style="" lang="EN-US">Hello Everyone,</span></p><p class="MsoNormal"><span style="" lang="EN-US"><br></span></p><p class="MsoNormal"><span style="" lang="EN-US">We have a 7
E1 SS7 linkset that above 70 calls load starts to flap constantly. The MTP goes
down, and comes back after 10 seconds or so. Sometimes it goes up and down a
few times in a row. <span style="mso-spacerun:yes"> </span>The flaps occur
every few minutes. We believe the TELCO is sending an LSSU message with an OS flag,
because of a weird behavior or instability in our side that we are trying to
determine.</span></p><p class="MsoNormal"><span style="mso-ansi-language:EN-US" lang="EN-US"><br></span></p>
<p class="MsoNormal"><span style="mso-ansi-language:EN-US" lang="EN-US">We can see
a lot of errors like:</span></p>
<p class="MsoNormal"><span style="" lang="EN-US"><br></span></p><p class="MsoNormal"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:53:30] NOTICE[31874] l4isup.c: read() failure, errno=11: Resource
temporarily unavailable</span></p><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:53:27] NOTICE[31876] mtp.c: Got event on link 'ostional1': 8 (0/11).</span><span style="mso-ansi-language:EN-US" lang="EN-US"> </span>
<p class="MsoNormal"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:53:32] NOTICE[31874] l4isup.c: read() failure, errno=11: Resource
temporarily unavailable</span></p>
<p class="MsoNormal"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 26
15:37:52] NOTICE[31191] l4isup.c: Short read on linkset "ostional"
CIC=153 (read only 0 of 160) errno=11 (Resource temporarily unavailable)
(supressed 953093).</span></p>
<p class="MsoNormal"><span style="" lang="EN-US"><br></span></p><p class="MsoNormal"><span style="mso-ansi-language:EN-US" lang="EN-US">Happening
around seconds of a flap condition. This issue is reproducible and occurs quite
often.</span></p>
<span style="font-size:11.0pt;line-height:115%;font-family:"Calibri","sans-serif";
mso-ascii-theme-font:minor-latin;mso-fareast-font-family:Calibri;mso-fareast-theme-font:
minor-latin;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";
mso-bidi-theme-font:minor-bidi;mso-ansi-language:EN-US;mso-fareast-language:
EN-US;mso-bidi-language:AR-SA" lang="EN-US">The link has no alarms, and can run stable for
hours with no load. With 30 or more calls the link behaves stable. </span><br clear="all"><br>
<p class="MsoNormal"><span style="mso-ansi-language:EN-US" lang="EN-US">Asterisk
1.6.2.18</span></p>
<p class="MsoNormal"><span style="mso-ansi-language:EN-US" lang="EN-US">ChanSS7 2.0</span></p>
<p class="MsoNormal"><span style="" lang="EN-US">dahdi-linux-complete-2.4.1.2+2.4.1</span></p><p class="MsoNormal"><span style="mso-ansi-language:EN-US" lang="EN-US">TE410P and TE420P<br></span></p>
<br>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:53:26] WARNING[9424] dsp.c: Inband DTMF is not supported on codec g729. Use
RFC2833</span><span style="mso-ansi-language:EN-US" lang="EN-US"> </span>
</p><p class="MsoNoSpacing"><b style="mso-bidi-font-weight:normal"><span style="mso-ansi-language:EN-US" lang="EN-US">This call was the last one been processed</span></b></p>
<p class="MsoNoSpacing"><b style="mso-bidi-font-weight:normal"><span style="mso-ansi-language:EN-US" lang="EN-US">We seem to get a bunch of these errors:</span></b><span style="mso-ansi-language:EN-US" lang="EN-US"> </span>
</p><p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:53:27] NOTICE[31876] mtp.c: Got event on link 'ostional1': 8 (0/11).</span></p>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:53:27] NOTICE[31876] mtp.c: Got event on link 'ostional1': 8 (0/11).</span></p>
<p class="MsoNoSpacing"><b style="mso-bidi-font-weight:normal"><span style="mso-ansi-language:EN-US" lang="EN-US">These errors are less common</span></b><span style="mso-ansi-language:EN-US" lang="EN-US"> </span>
</p><p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:53:27] NOTICE[31874] l4isup.c: read() failure, errno=11: Resource
temporarily unavailable</span></p>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:53:27] NOTICE[31876] mtp.c: Got event on link 'ostional1': 8 (0/11).</span></p>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">… <b style="mso-bidi-font-weight:normal">Many more of this errors</b></span></p>
<p class="MsoNoSpacing"><b style="mso-bidi-font-weight:normal"><span style="mso-ansi-language:EN-US" lang="EN-US">At some point we received the LSSU with OS from
the TELCO and the link changes to down</span></b><b style="mso-bidi-font-weight:normal"><span style="mso-ansi-language:EN-US" lang="EN-US"> </span></b>
</p><p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:53:27] NOTICE[31876] mtp.c: Got status indication 'OS' while INSERVICE on
link 'ostional1'.</span></p>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:53:27] WARNING[31876] chan_ss7.c: MTP is now DOWN on link 'ostional1'.</span></p>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:53:27] NOTICE[31876] mtp.c: MTP changeover last_ack=7, last_sent=7, from
schannel 31, no INSERVICE schannel found</span></p>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:53:27] NOTICE[31876] mtp.c: Failover not possible, no other signalling link
and no other host available.</span></p>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:53:27] WARNING[31876] chan_ss7.c: MTP is now DOWN on link 'ostional1'.</span></p>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:53:27] NOTICE[31876] mtp.c: Got status indication 'OS' while INSERVICE on
link 'ostional2'.</span></p>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:53:27] WARNING[31876] chan_ss7.c: MTP is now DOWN on link 'ostional2'.</span></p>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:53:27] NOTICE[31876] mtp.c: MTP changeover last_ack=11, last_sent=12, from
schannel 31, no INSERVICE schannel found</span></p>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:53:27] NOTICE[31876] mtp.c: Failover not possible, no other signalling link
and no other host available.</span></p>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:53:27] WARNING[31876] chan_ss7.c: MTP is now DOWN on link 'ostional2'.</span></p>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:53:27] NOTICE[31876] mtp.c: Got event on link 'ostional1': 6 (0/11).</span></p>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">… </span></p>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US"></span><span style="" lang="EN-US"><span style="mso-spacerun:yes"></span>[Jun 28 01:53:27] NOTICE[31876] mtp.c: Got
event on link 'ostional1': 6 (0/11).</span></p><p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:53:28] NOTICE[31874] l4isup.c: read() failure, errno=11: Resource
temporarily unavailable</span></p><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:53:29] NOTICE[9244] l4isup.c: Short read on linkset "ostional"
CIC=101 (read only 0 of 160) errno=11 (Resource temporarily unavailable)
(supressed 1822).</span>
<br><b><br>Some seconds later the link will come back</b><br><br>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">Jun 28
01:54:08] WARNING[31876] chan_ss7.c: MTP is now UP on link 'ostional2'.</span></p>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:54:08] NOTICE[31876] mtp.c: Sending TRA to peer on link 'ostional2'....</span></p>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:54:08] WARNING[31876] chan_ss7.c: MTP is now UP on link 'ostional1'.</span></p>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:54:08] NOTICE[31876] mtp.c: Sending TRA to peer on link 'ostional1'....</span></p>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:54:11] NOTICE[31876] l4isup.c: T1 timeout (waiting for RLC) CIC=175.</span></p>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:54:18] NOTICE[31876] l4isup.c: T1 timeout (waiting for RLC) CIC=59.</span></p>
<p class="MsoNoSpacing"><span style="mso-ansi-language:EN-US" lang="EN-US">[Jun 28
01:54:18] NOTICE[31876] l4isup.c: T1 timeout (waiting for RLC) CIC=101.</span></p><span style="mso-ansi-language:EN-US" lang="EN-US"> </span><b style=""><span style="font-size: 12pt;" lang="EN-US"></span></b><p class="MsoNoSpacing">
<b style="mso-bidi-font-weight:normal"><span style="font-size:12.0pt;mso-ansi-language:EN-US" lang="EN-US">We can see calls coming in
again</span></b> </p><p class="MsoNoSpacing">What conditions could generate the CO Switch to send an LSSU with an OS signal.</p><p class="MsoNoSpacing">Could this because of line errors, slips or problems on the line? How could we check that from the asterisk side?<br>
</p><p class="MsoNoSpacing">-- <br></p><br>Robert<br>