<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">CM does and phones do not do RTCP. However, it looks like CUCM may default the RTCP port to 4001 during some capabilities and port exchanges.<div><br><div><div>On Dec 1, 2011, at 3:46 PM, Lelio Fulgenzi wrote:</div><br class="Apple-interchange-newline"><span class="Apple-style-span" style="border-collapse: separate; font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><span class="Apple-style-span" style="font-family: Verdana; font-size: 13px; ">What is UDP traffic destined to 4001 all about?<br></span></span></div><br></div></body></html>