A SIP user agent (UA) is a logical

A SIP user agent (UA) is a logical network end-point used to create or receive SIP messages and thereby manage a SIP session. A SIP UA can perform the role of a User Agent Client (UAC), which sends SIP requests, and the User Agent Server (UAS), which receives the requests and returns a SIP response. These roles of UAC and UAS only last for the duration of a SIP transaction.[7]
A SIP phone is an IP phone that implements SIP user agent and server functions, which provide the traditional call functions of a telephone, such as dial, answer, reject, hold/unhold, and call transfer.[12][13] SIP phones may be implemented as a hardware device or as a softphone. As vendors increasingly implement SIP as a standard telephony platform, often driven by 4G efforts, the distinction between hardware-based and software-based SIP phones is being blurred and SIP elements are implemented in the basic firmware functions of many IP-capable devices. Examples are devices from Nokia and BlackBerry.[14]
In SIP, as in HTTP, the user agent may identify itself using a message header field 'User-Agent', containing a text description of the software/hardware/product involved. The User-Agent field is sent in request messages, which means that the receiving SIP server can see this information. SIP network elements sometimes store this information,[15] and it can be useful in diagnosing SIP compatibility problems.

Kết quả (Anh) 2:

A SIP user agent (UA) is a logical end-point network used to create or receive SIP messages and thereby manage a SIP session. A SIP UA can thực the role of a User Agent Client (UAC), sends SIP requests mà, and the User Agent Server (UAS), receives the requests and returns mà a SIP response. These roles of UAC and UAS for the duration of last only a SIP transaction. [7]
A SIP is an IP phone SIP user agent implements mà phone and server functions, mà cung the traditional functions of a telephone call, như dial, answer , reject, hold / Resume, and call transfer. [12] [13] SIP phones as a hardware lẽ thực device or as a softphone. As vendors increasingly implements SIP telephony as a standard platform, often Do driven by 4G efforts into, the Distinction hardware-based and software giữa-based SIP phones and SIP is being blurred in the basic elements are thực firmware functions of many IP-capable devices. Examples are from Nokia and BlackBerry devices. [14]
In SIP, as in HTTP, the user agent using a sewing diện chính nó message header field 'User-Agent', containing a text description of the software / hardware / product INVOLVED. The User-Agent field in the request is sent messages, mà Receiving the SIP server vì can see this information. SIP network elements sometimes store this information, [15] and it can be SIP compatibility ích in diagnosing problems.