[Home](./index.md) > [sip.js](./sip.js.md) > [InviteUserAgentServer](./sip.js.inviteuseragentserver.md) ## InviteUserAgentServer class INVITE UAS. Signature: ```typescript export declare class InviteUserAgentServer extends UserAgentServer implements IncomingInviteRequest ``` ## Remarks 13 Initiating a Session https://tools.ietf.org/html/rfc3261\#section-13 13.1 Overview https://tools.ietf.org/html/rfc3261\#section-13.1 13.3 UAS Processing https://tools.ietf.org/html/rfc3261\#section-13.3 ## Constructors | Constructor | Modifiers | Description | | --- | --- | --- | | [(constructor)(core, message, delegate)](./sip.js.inviteuseragentserver._constructor_.md) | | Constructs a new instance of the InviteUserAgentServer class | ## Properties | Property | Modifiers | Type | Description | | --- | --- | --- | --- | | [core](./sip.js.inviteuseragentserver.core.md) | | UserAgentCore | | ## Methods | Method | Modifiers | Description | | --- | --- | --- | | [accept(options)](./sip.js.inviteuseragentserver.accept.md) | | 13.3.1.4 The INVITE is Accepted The UAS core generates a 2xx response. This response establishes a dialog, and therefore follows the procedures of Section 12.1.1 in addition to those of Section 8.2.6. https://tools.ietf.org/html/rfc3261\#section-13.3.1.4 | | [dispose()](./sip.js.inviteuseragentserver.dispose.md) | | | | [progress(options)](./sip.js.inviteuseragentserver.progress.md) | | 13.3.1.1 Progress If the UAS is not able to answer the invitation immediately, it can choose to indicate some kind of progress to the UAC (for example, an indication that a phone is ringing). This is accomplished with a provisional response between 101 and 199. These provisional responses establish early dialogs and therefore follow the procedures of Section 12.1.1 in addition to those of Section 8.2.6. A UAS MAY send as many provisional responses as it likes. Each of these MUST indicate the same dialog ID. However, these will not be delivered reliably.If the UAS desires an extended period of time to answer the INVITE, it will need to ask for an "extension" in order to prevent proxies from canceling the transaction. A proxy has the option of canceling a transaction when there is a gap of 3 minutes between responses in a transaction. To prevent cancellation, the UAS MUST send a non-100 provisional response at every minute, to handle the possibility of lost provisional responses. https://tools.ietf.org/html/rfc3261\#section-13.3.1.1 | | [redirect(contacts, options)](./sip.js.inviteuseragentserver.redirect.md) | | 13.3.1.2 The INVITE is Redirected If the UAS decides to redirect the call, a 3xx response is sent. A 300 (Multiple Choices), 301 (Moved Permanently) or 302 (Moved Temporarily) response SHOULD contain a Contact header field containing one or more URIs of new addresses to be tried. The response is passed to the INVITE server transaction, which will deal with its retransmissions. https://tools.ietf.org/html/rfc3261\#section-13.3.1.2 | | [reject(options)](./sip.js.inviteuseragentserver.reject.md) | | 13.3.1.3 The INVITE is Rejected A common scenario occurs when the callee is currently not willing or able to take additional calls at this end system. A 486 (Busy Here) SHOULD be returned in such a scenario. https://tools.ietf.org/html/rfc3261\#section-13.3.1.3 |