sec-okay. This option tag displays support for the security agreement mechanism. When used in the Require or Proxy-Require headers, it specifies that proxy servers must use the security agreement mechanism. When used in the Supported header, it indicates that the client user agent supports the security agreement mechanism. When used in the Require header of responses 494 (security agreement required) or 421 (extension required), it indicates that the user agent client should use the mechanism of the security agreement. Call information. This field contains additional information about the caller or caller, depending on whether they are included in a request or response. The purpose of the URI is described by the “purpose” parameter. The “icon” parameter refers to an image that is suitable as an iconic representation of the caller or the caller. The “info” parameter describes the caller or caller in general, for example via a web page. For example, the card parameter provides a business card in vCard or LDIF format. Additional tokens can be registered with IANA.
Using the Call Information header field may pose a security risk. If a caller retrieves the URIs provided by a malicious caller, there may be a risk that the person called will display inappropriate or offensive content, dangerous or illegal content, etc. Therefore, it is recommended that a UA display the information in the Call Information header field only if it can verify and trust the authenticity of the item from which the header field originated. It does not have to be the AU of peers; A proxy can include this header field in requests. Event package. (RFC 3265) An event package is an additional specification that defines a set of status information to be reported by a notifier to a subscriber. Event packages also define additional syntax and semantics based on the infrastructure defined in this document that is required to submit this status information. Server. Contains information about the software used by UAS to manage the request. Disclosure of the specific software version of the server can make the server more vulnerable to attacks on software known to contain vulnerabilities.
Implementers MUST make the server header field a configurable option. Alert information. If the Alert Information header field exists in an INVITE request, it specifies a different ringtone than the UAS. If the Alert Information header field is present in a 180 response (ringtone), it specifies a different callback tone to UAC. A typical use is for a proxy to insert this header field to provide a distinctive ring function. The Alert Information header field may present security risks. In addition, a user SHOULD be able to selectively disable this feature. UAC kernel. (RFC 3261) The set of processing functions required by UAC that reside above the transaction and transport layers. The call has arrived at its destination and this sends back that it “rings”.
With Lync with Early Media, endpoints can first try to connect via ICE before the header rings. (RFC 3261) A component of a SIP message that transmits information about the message. It is structured as a sequence of header fields. SIP response codes and corresponding root cause expressions were originally defined in RFC 3261. [1] This RFC also defines a SIP parameter record from the Internet Assigned Numbers Authority (IANA) so that other RFCs can provide more response codes. [1]:ยง27[2]. . [RFC 3398] Integrated Services Digital Network (ISUP) mapping to SIP mapping (ISDN) to session initiation protocol. Prerequisite. (RFC 3312) A supplier MUST include this tag in the Require header field if the offer contains one or more “mandatory” force tags. If all force tags in the description are “optional” or “none”, the provider MUST include that tag in a supported Header field or a Required header field. Target update request.
(RFC 3261) A target update request sent in a dialog box is defined as a request that can change the remote destination of the dialog box. [RFC 4458] Session Initiation Protocol (SIP) URI for applications such as voice mail and interactive voice response (IVR). Content type, c. Specifies the media type of the message body sent to the recipient. This header field MUST exist if the body is not empty. If the body is empty and there is a content type header field, this indicates that the body of the particular type has a length of zero (for example. B an empty audio file). gruu. This option tag is used to identify the GRUU URI extension, GlobalLy Routable User Agent. When used in a Supported header, it indicates that a user agent understands the extension. When used in a Require header field of a REGISTER query, it indicates that the registrar is not expected to process the registry unless it supports the GRUU extension. [RFC 4354] A Session Initiation Protocol (SIP) event package and data format for various parameters to support the Push-to-Talk over Cellular (PoC) service.
Content layout. Describes how to interpret the message body or, in the case of multipart messages, a portion of the message body by User Account Control or UAS. Proxy, proxy server. (RFC 3261) A middle-end entity that acts as both a server and a client to make requests on behalf of other clients. A proxy server primarily plays the role of routing, which means that its job is to ensure that a request is sent to another entity that is “closer” to the target user. Proxies are also useful for enforcing policies (for example. B to ensure that a user is allowed to make a call). A proxy interprets and rewrites parts of a request message as needed before forwarding them. Accept. If the Accept header field does not exist, the server MUST set the default APPLICATION/sdp MIME value. An empty Accept header field means that no format is accepted. The transaction has been terminated, but the customer gets the information that they need to use in another way downstream.
(RFC 3261) The direction of message forwarding in a transaction that refers to the direction in which requests flow from the user agent client to the user agent server. . [RFC 4244] Extension of Session Initiation Protocol (SIP) for request history information. The server has a pending request from the same dialog box. Subscription. (RFC 3265) A subscription is a set of application states associated with a dialog box. This application state contains a pointer to the associated dialog box, the name of the event package, and optionally an identification token. Event packages define additional information about the status of the subscription.
By definition, subscriptions exist with both a subscriber and a requester. Faulty SIP protocol extension used, not understood by the server. The server needs a specific extension that is not listed in the Supported header. Error information. Provides a pointer to additional information about the response to the error status. Regular transaction. (RFC 3261) Any transaction that uses a method other than INVITE, ACK, or CANCEL. Preliminary information indicating that the server performs other actions and therefore cannot yet send a final response. 2xx: Success.
The action was successfully received, understood and accepted. [RFC 4488] Remove implicit subscriptions to the REFINE method from session initiation protocol (SIP). . See r. This field appears only in a REFER request. It provides a URL for SEO. . Accept-Resource-Priority. This field lists the resource values that a SIP user agent server wants to process. Path. This is a SIP extension header field with syntax very similar to the record route header field. It is used in conjunction with SIP REGISTER queries and with 200 class messages in response to REGISTER.
A path header field CAN be inserted into a REGISTER by any SIP node traversed by this request. Like the path header field, sequential path header fields are evaluated in the order in which they exist in the request, and the path header fields CAN be combined into a compound path header into a single path header field. The registrar reflects the accumulated path in the REGISTER response and the intermediate nodes propagate it to the original UA. The original UA will therefore be informed of the inclusion of nodes in its registered path and MAY use this information in other functions outside the scope of this document. The difference between Path and Record Route is that Path applies to REGISTER and 200 class responses to REGISTER. Save the route and cannot be set in REGISTER for backward compatibility. In addition, the vector defined by Record-Route applies only to queries in the dialog box that have configured this record route, while the vector defined by Path applies to future dialog boxes. TU, transaction users. (RFC 3261) The log processing layer that resides above the transaction layer. Transaction users include the core of UAC, the core of the UAS, and the core of the proxy. Application errors are negative acknowledgements of receipt.
The previous message could not be processed. An, t. Specifies the logical recipient of the request. The optional “display name” must be rendered by a human user interface. The tag parameter serves as a general mechanism for identifying dialog boxes. Path. A SIP UA that supports the Path Extension header field contains this option tag as a header field value in a header field supported in all requests generated by that UA. Intermediate proxies can use the presence of this option tag in a REGISTER query to determine whether to offer the path service for that request.
If an intermediate proxy requires the registrar to support the path for a request, it includes that option tag as a header field value in a Requires header field in that request. . . .