<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office">
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<!--[if gte mso 9]>
<xml>
<o:OfficeDocumentSettings>
<o:AllowPNG/>
<o:PixelsPerInch>96</o:PixelsPerInch>
</o:OfficeDocumentSettings>
</xml>
<![endif]-->
<style type="text/css">* a:hover{cursor:pointer;}</style>
<style>body {-webkit-animation:bugfix infinite 1s;}@-webkit-keyframes bugfix {from {position:relative;}to {position:relative;}}</style>
</head>
<body style="word-wrap:normal; word-break:break-word;">
<style>a {word-wrap:normal;word-break:break-word;}.background-contain {background-size:contain;}@media only screen and (max-width:600px) {.container {-webkit-text-size-adjust:none !important;}.container,.palm-one-whole {width:100% !important;min-width:100% !important;}.palm-one-half {width:50% !important;min-width:50% !important;box-sizing:border-box;}blockquote .container,blockquote .container div,blockquote .container table {width:auto !important;min-width:0 !important;position:relative !important;}img {max-width:100%;}.border-outer,.border-middle,.border-inner,.inner,[title="separator"] {width:100% !important;}.innercell {padding:8px !important;}.palm-block {display:block !important;}td.palm-one-whole {display:inline-block !important;padding:0;}td.palm-one-whole:first-child:not(:only-child) {margin-bottom:16px;}td.hostname {padding-top:3px !important;}}@media only screen and (min-width:601px) {.preview-card {max-width:600px !important;}}@media only screen and (min-device-width :320px) and (max-device-width :568px),only screen and (min-device-width :768px) and (max-device-width :1024px),only screen and (max-device-width:640px),only screen and (max-device-width:667px),only screen and (max-width:480px){.container {width:100% !important;min-width:100% !important;}.p,.small,li,font[size="2"],font[size="3"] {font-size:1em !important;}}@media only screen and (min-device-width :320px) and (max-device-width :568px),only screen and (min-device-width :768px) and (max-device-width :1024px),only screen and (min-device-width :1224px) {.message-wrapper {padding-top:6px;}.apple-only[style] {display:block !important;max-height:none !important;line-height:normal !important;overflow:visible !important;height:auto !important;width:100% !important;position:relative !important;}.no-apple {display:none !important;}form {font-size:inherit;}input[type="text"] {height:43px;padding-left:4px !important;}button:hover {cursor:pointer;}}@media only screen and (min-device-width :1224px) {.apple-mail-form {display:block !important;background-color:white !important;}}* [office365] .outlook-com-hidden {display:none !important;}* [office365] .outlook-com-button {display:block;}* [office365] .outlook-com-only {display:block !important;max-height:none !important;line-height:normal !important;overflow:visible !important;height:auto !important;width:100% !important;position:relative !important;}</style>
<!--[if (gte mso 9)|(IE)]>
<style>a,body {font-family:'Calibri',Arial,sans-serif;}img {border:none !important;-ms-interpolation-mode:bicubic;}td {mso-line-height-rule:exactly !important;}.mso-card-inner table {border-collapse:collapse !important;mso-table-lspace:0pt;mso-table-rspace:0pt;vertical-align:top;}.outlook-com-only {display:none !important;font-size:0 !important;}#mso-one-whole {width:100% !important;}.border-outer,.border-middle,.border-inner {border:none !important;}.border-middle,.border-inner {width:100% !important;}.mso-border-outer,.mso-border-middle,.mso-border-inner {padding:1px;}.mso-border-outer {background-color:rgb(245,255,255);}.mso-border-middle {background-color:rgb(223,246,255);}.mso-border-inner {background-color:rgb(153,176,225);}</style>
<![endif]-->
<table class="container" lang="container" border="0" cellpadding="0" cellspacing="0" valign="top" style="width:100%; margin-top:6px;">
<tr>
<td valign="top" class="message-wrapper" style="line-height: 1.31; color: #222; font-family: arial, sans-serif;">
<!--[if mso]><table border="0" cellpadding="0" cellspacing="0" valign="top" style="border-collapse:separate;"><tr><td valign="top"><![endif]-->
<div>This is an interesting one. I'm running into issues with a fax application for a few numbers that are playing back a strange tone I have yet to identify. I originally thought it was FAS with international ringback, but it's occurring on a variety of numbers on various networks. The tone is playing immediately upon answer. Any help identifying what is causing this tone or what it is intended for is appreciated.</div><div><br></div><div>The numbers are all fax lines and do get the proper CED after this tone. I can't find any matching tone in the T.30 ITU-T rec. As best I can figure, it's 400Hz with a 0.03s period on/off cycle, played 1s on 2s off. Listen at the below link. Sorry for the compression; email me and I can send you the original wav recording. </div><div><br></div><div>https://clyp.it/vcq010th</div><div class="mixmax_signature"><br></div><img align="left" width="0" height="0" style="border:0; width:0px; height:0px;" src="https://app.mixmax.com/api/track/v2/oifmtMa69g0d9tu2k/i02bj5SZ0V3byd3bsZGQ39mcnpmI/IyZy9mLzB3blNWavZHQzB3blNWavZnI/gIzB3TlNWavZlI" alt="">
<!--[if mso]></td></tr></table><![endif]-->
</td>
</tr>
</table>
</body>
</html>