<HTML><BODY style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; "><BR><DIV><DIV>On 14 Jan 2006, at 10:47, Koopmann, Jan-Peter wrote:</DIV><BR class="Apple-interchange-newline"><BLOCKQUOTE type="cite"><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Hi,</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><BR></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">this is the scenario:</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><BR></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">One * is placed in a central location with more than enough up/down</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">bandwidth. One * is placed behind a DSL 3000/384. Both * are linked via</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">IAX trunking. Everything is fine until the upload channel of the remote</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">site is filled with a download, then heavy voice distortion starts. Well</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">of course this is expected. So I fooled around with HFSC QoS scheduling</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">on the remote site Linux machine. The scheduling seems to work as the</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">TOS marked traffic is put in the correct queue and the upload bandwith</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">for other applications is going down.</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><BR></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">BUT: The voice quality problems definatly stay when using IAX. The funny</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">part: Doing the same with SIP shows no big problems. SIP calls to</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">T-Online work nicely and even if I change the * <-> * link from IAX to</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">SIP everything is fine even with full up-/downloads on the remote DSL</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">connection.</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><BR></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">My conclusion would be that this depends on the IAX implementation</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">somehow. I tried different settings for jitterbuffer, trunk and</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">trunktimestamp all with the same result. This currently means we go back</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">to SIP for *<->* linkage.</DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><BR></DIV><DIV style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Any ideas? If I should rather post this over in -dev please let me know!</DIV></BLOCKQUOTE><DIV><BR class="khtml-block-placeholder"></DIV><DIV>That is weird, you would expect IAX to do better than SIP (bandwidth wise)</DIV><DIV>especially if you have trunking enabled.</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>Some questions :</DIV><DIV><SPAN class="Apple-tab-span" style="white-space:pre"> </SPAN>1) are you sure IAX trunking is actually happening ?</DIV><DIV><SPAN class="Apple-tab-span" style="white-space:pre"> </SPAN>2) what codecs are you using. Are the codecs the same for IAX as</DIV><DIV>for sip?</DIV><DIV><SPAN class="Apple-tab-span" style="white-space:pre"> </SPAN>3) is it possible that some of the network hardware is 'sip aware'</DIV><DIV>and is doing some additional QOS magic for you ?</DIV><DIV><SPAN class="Apple-tab-span" style="white-space:pre"> </SPAN>4) How many simultaneous calls are you running between the 2 endpoints?</DIV><DIV><SPAN class="Apple-tab-span" style="white-space:pre"> </SPAN>5) What happens if you turn trunking off ? </DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>Tim.</DIV><DIV><BR class="khtml-block-placeholder"></DIV></DIV><BR><DIV> <P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica"><A href="http://www.westhawk.co.uk">http://www.westhawk.co.uk</A>/</FONT></P> </DIV><BR></BODY></HTML>