<div>
It really depends on the phone's built it hardware. If it's a built-in switch (instead of a hub), you're on a separate collision domain, and therefor will not see traffic destined for the phone. You'll need a hub in line, or have the phone attached to a managed switch that will allow port mirroring. 
</div>


ScreenHunter-17-Nov.-12-13.21.gif

<div>
Nice. I was unaware of this setting, good to know. Don't think I've ever seen that on a Polycom
</div>


<div>
Thanks for the reply BooST.
</div>


<div>
<div class="content wysiwyg-content">
I am troubleshooting an intermittent problem (one way audio) on some calls. &nbsp;I have Cisco 7945G phones and users' laptops connect through the phone. &nbsp;When I was at another company when I ran the sniffer on the laptop I could see all the phone traffic. &nbsp;But that appears to no longer be the case. &nbsp;Where can I modify the behavior such that phone traffic DOES appear at the NIC of the attached PC? &nbsp;Thanks!
</div>
</div>


I am troubleshooting an intermittent problem (one way audio) on some calls.  I have Cisco 7945G phones and users' laptops connect through the phone.  When I was at another company when I ran the sniffer on the laptop I could see all the phone traffic.  But that appears to no longer be the case.  Where can I modify the behavior such that phone traffic DOES appear at the NIC of the attached PC?  Thanks!

It really depends on the phone&#39;s built it hardware. If it&#39;s a built-in switch (instead of a hub), you&#39;re on a separate collision domain, and therefor will not see traffic destined for the phone. You&#39;ll need a hub in line, or have the phone attached to a managed switch that will allow port mirroring. 

Nice. I was unaware of this setting, good to know. Don&#39;t think I&#39;ve ever seen that on a Polycom

Cisco Phone: How PC can see phone traffic

I am troubleshooting an intermittent problem (one way audio) on some calls.  I have Cisco 7945G phones and users&#39; laptops connect through the phone.  When I was at another company when I ran the sniffer on the laptop I could see all the phone traffic.  But that appears to no longer be the case.  Where can I modify the behavior such that phone traffic DOES appear at the NIC of the attached PC?  Thanks!

IP telephony (Internet Protocol telephony) is a general term for the technologies that use the Internet Protocol's packet-switched connections to exchange voice, fax, and other forms of information that have traditionally been carried over the dedicated circuit-switched connections of the public switched telephone network (PSTN). Using the Internet, calls travel as packets of data on shared lines, avoiding the tolls of the PSTN. The challenge in IP telephony is to deliver the voice, fax, or video packets in a dependable flow to the user.

IP Telephony

Voice over IP (VoIP) is a methodology and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. Other terms commonly associated with VoIP are IP telephony, Internet telephony, broadband telephony, and broadband phone service. The term specifically refers to the provisioning of communications services (voice, fax, SMS, voice-messaging) over the public Internet, rather than via the public switched telephone network (PSTN).  Examples of the VoIP protocols are H.323, Media Gateway Control Protocol (MGCP), Session Initiation Protocol (SIP), H.248 (also known as Media Gateway Control (Megaco)), Real-time Transport Protocol (RTP), Real-time Transport Control Protocol (RTCP), Secure Real-time Transport Protocol (SRTP), Session Description Protocol (SDP), and Inter-Asterisk eXchange (IAX).