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I have a small satellite office that i am trying to run a couple of Cisco phones over a VPN. &nbsp;I know this isn't the most desirable way and calls over vpn are prone to jitter. &nbsp;I can still see some benefit in adding QoS to the source and destination side of the tunnel especially if the source is maxing out its connection.<br />
<br />
I have been told that Cisco phones use &quot;cost&quot; as default for QoS. <br />
(1) does anyone have a clarify explanation on this? and is there a way to utilize this in a non Cisco environment?<br />
<br />
(2) do Cisco phone default tag there traffic using any of the DSCP tags? such as AF41,42 or EF?<br />
<br />
(3) Any advice in general would be appreciated here on this. <br />
<br />
Regards, <br />
<br />
-Steve-
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I have a small satellite office that i am trying to run a couple of Cisco phones over a VPN.  I know this isn't the most desirable way and calls over vpn are prone to jitter.  I can still see some benefit in adding QoS to the source and destination side of the tunnel especially if the source is maxing out its connection.

I have been told that Cisco phones use "cost" as default for QoS. 
(1) does anyone have a clarify explanation on this? and is there a way to utilize this in a non Cisco environment?

(2) do Cisco phone default tag there traffic using any of the DSCP tags? such as AF41,42 or EF?

(3) Any advice in general would be appreciated here on this. 

Regards, 

-Steve-

Cisco phones default voip QoS tagging over a vpn

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

Telecommunication occurs when the exchange of information between two or more entities (communication) includes the use of technology. Communication technology uses channels to transmit information (as electrical signals), either over a physical medium (such as signal cables), or in the form of electromagnetic waves. The word is often used in its plural form, telecommunications, because it involves many different technologies.

Telecommunications

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).