The feature is a DSP-software feature in 15.1(1)T. This means it should not be protocol dependent. And though it is a DSP feature, it is still not hardware dependent (per our last thread).<br><br>To my recollection, you should be able to use fax-passthrough with G711 with CUCM. I seem to remember doing this many times, but the only scenario I can't remember if it works correctly is G729->G711 switchover with CUCM with passthrough.<br>
<br>The modem passthrough recommendation may be based in the pre-SG3 era, and not be updated in the document. The <a href="http://cisco.com">cisco.com</a> fax documents aren't particularly great sometimes. I will be interested to see whether or not the SG3 makes T38 more stable. My thought it yes, and I would personally start using T38 as my default rather than modem passthrough with this new feature.<br>
<br>Modem passthrough pseudo-supported SG3 before. Sometimes it would work, sometimes not, because the DSPs were incapable of promising SG3 speeds. That should also be changed now, as they support 56k speeds.<br><br>-nick<br>
<br><br><br><div class="gmail_quote">On Fri, Apr 9, 2010 at 9:54 AM, Lelio Fulgenzi <span dir="ltr"><<a href="mailto:lelio@uoguelph.ca">lelio@uoguelph.ca</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<div><div style="font-family: Verdana; font-size: 10pt; color: rgb(0, 0, 0);"><div style="font-family: Verdana; font-size: 10pt; color: rgb(0, 0, 0);">I thought I'd start a new thread to help with future searches.<br>
<br>I took a closer look at that link I sent out earlier, the one that pointed me to CUBE configuration, and it turns out there is a section in there that talks about:<br><br><div style="margin-left: 40px;"><hr style="width: 100%; min-height: 2px;">
<span style="font-weight: bold;">SG3 Fax Support on Cisco TDM-IP Voice Gateways and Cisco UBE Platforms </span><br><br><a href="http://www.cisco.com/en/US/docs/ios/voice/cube/configuration/guide/vb-gw-config.html#wp1423706" target="_blank">http://www.cisco.com/en/US/docs/ios/voice/cube/configuration/guide/vb-gw-config.html#wp1423706</a><br>
<hr style="width: 100%; min-height: 2px;"><br></div>While it goes in depth about relay, for fax pass-through, it simply points to an old v12.4T document (<a href="http://www.cisco.com/en/US/docs/ios/voice/fax/configuration/guide/vf_cfg_fx_passthr_ps6441_TSD_Products_Configuration_Guide_Chapter.html" target="_blank">link</a>). The <a href="http://www.cisco.com/en/US/docs/ios/voice/fax/configuration/guide/vf_cfg_fx_passthr_ps10592_TSD_Products_Configuration_Guide_Chapter.html" target="_blank">new one</a> (for v15.1) doesn't seem to go into any specific discussion about SG3 speeds, in fact, all it talks about is SG3 downgrading to G3.<br>
<br>In reading it more closely, it mentions only: MGCP, H323, and SIP. Is SCCP out?<br><br>In reading it even more closely, it mentions that if you're using all Cisco gateways, you should use modem passthrough.<br><div style="margin-left: 40px;">
<br><span><p>
<b>Note </b><img src="" alt="" border="0" height="2" width="1">Modem pass-through is preferred if all of the involved gateways are Cisco IOS gateways.<br></p></span></div><br>And even more reading says if you're using CCM, you MUST use modem passthrough.<br>
<br><div style="margin-left: 40px;"><span><b>Note </b><img src="" alt="" border="0" height="2" width="1">If you need to configure fax pass-through to work with Cisco CallManager (CCM), you must use the <b>modem passthrough nse</b> command. The f<b>ax protocol pass-through </b>command does not work with CCM, which relies on NSE information.
</span></div><br>So what's the deal? <br><ul><li>Is SG3 supported on modem passthrough which I now must use? <br></li><li>Does that mean I can stick with SCCP on my VG224, since SCCP supports modem passthrough?</li></ul>
<br><br><br><br><br><br><br><div style="margin-left: 40px;"><br></div><br>keywords: super G3 faxing fas passthrough fax pass-through confusing<br><br>---<br><font color="#888888">Lelio Fulgenzi, B.A.<br>Senior Analyst (CCS) * University of Guelph * Guelph, Ontario N1G 2W1<br>
(519) 824-4120 x56354 (519) 767-1060 FAX (JNHN)<br>^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^<br>Cooking with unix is easy. You just sed it and forget it. <br> - LFJ (with apologies to Mr. Popeil)<br>
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