Routes: Special

AG Projects RTC Platforms (Routing Guides)

This guide describes the special routing not mentioned in other guides.

Call Diversion

A user may chose to divert his/her calls based on various conditions (like unconditional, busy or not online) to another SIP address including PSTN destinations. Diverted calls are always charged to the user who enabled them. For every call diversion, a new Diversion header is appended to the original SIP request.

File Transfer

File transfer based on MSRP protocol is similar to a regular SIP audio session. Instead of RTP media , MSRP is used for establishing a media channel. A MSRP relay is used to traverse the NAT.

Emergency Calls

Emergency calls refer to dialing short numbers usually associated with emergency services like police or fire-brigade (e.g. 112 or 911). When a session is setup to a short number designated as an emergency number (in the SIP Proxy configuration), a database lookup is performed by the proxy in the emergency_mapping table. Based on the region attribute provisioned with the SIP account, the final destination corresponding with the emergency number is looked up. Only local users can dial an emergency number.

See Provisioning: Emergency Numbers for more information.

XMMP gateway

The platform can be setup to federate with remote XMPP domains using a gateway function. The functionality is described at:

http://sylkserver.ag-projects.com/projects/sylkserver/wiki/DesignXMPP

PBX Media Functions

Functions involving playing media in the middle of a call setup are not possible by the design of a SIP Proxy. Features like:

• IVR
• Auto-attendant
• Call queues and ACD
• Listen-in and barge-in
• Call parking
• Music on hold (MoH)

are not performed by a SIP Proxy. Such functions can be implemented only by dedicated IP-PBX added to the platform. The platform is used to route calls between such PBXs, from the MSP perspective these PBX are seen as SIP trunks connected to the platform.

Next Steps

Continue by:

• learning about Routes: End-Point or
• learning about Routes: MSRP media or
• learning about Routes: PBX or Trunk or
• learning about Routes: MS Teams; or
• learning about Routes: PSTN or
• learning about Routes: Presence or
• going back to the Overview.