Unicom Gateway

Unicom Gateway

Unified Communications

Unicom Gateway is a scalable, extensible, cloud-ready Unified Communications (UC) platform that offers real-time bridging from SIP-based media control channel to web-enabled enterprise applications and distributed cloud services.

The gateway includes a carrier-grade implementation of SIP 2.0 compliant User Agent Server (UAS) capable of handling a high volume of media control requests coming from SIP endpoints and intermediaries. Downstream of voice signaling layer, Unicom Gateway performs real-time translation of SIP requests to XML messages continuously published into asynchronous delivery channel. Operational Support Systems can use HTTP or JMS interface to subscribe for the media control messages of their interest.

Unicom Gateway seamlessly integrates with a variety of systems, including API Gateways, Micro-services Platforms, Application Servers and Message Brokers.

Session Lifecycle Management and Call Routing

Session Control allows creating, modifying and terminating media sessions with one or more participants who are authenticated and authorized for using specific multimedia services delivered over IP networks.

• Implements industry standard, SIP 2.0 based User Agent Server (UAS) to handle media signaling.
• Supports phone and push-to-talk radio call routing via PSTN branch-office exchange devices.

Media Event Subscription and Real-time Alerting

Event Notification provides an extensible framework by which SIP endpoints can request asynchronous notification from remote nodes, indicating that certain events have occurred as part of their collaboration.

• Allows specialized event packages, such as callback services, buddy lists and message waiting indication.
• Supports event handling and real-time alerting to VoIP and PSTN endpoints via PINT 1.0 compatibility.

Media Event State Advertising and Composition

State Publication provides a framework for User Agent Clients (UAC) to publish their event state to UAS responsible for compositing and distributing it to interested parties via Event Notification mechanism.

• Allows SIP endpoints to publish their unique state, and UAS to generates composite state for distribution.
• Supports publication of presence state in compliance with the Presence Information Data Format (PIDF).

In-session Media Control Information Exchange

Information Signaling allows to carry application level information between SIP endpoints using media control path, providing a general-purpose mechanism for transferring arbitrary data within a media session.

• Allows specialized info packages, such as IVR dial-tones, video-conferencing and video-streaming.
• Supports DTMF, MSML, MSCML and RTCP/XML message transport and real-time processing.

Call Management on Behalf of Other Parties

Third-party Call Control allows to establish a media call in which communication is actually between other parties. It is typically used for operator assistance, click-to-dial services and audio/video conferencing.

• Provides general ability to manipulate calls between media servers, conferencing servers and endpoints.
• Allows coupling of media signaling with media resource reservation using SDP compatible metadata.

Presence State Subscription and Notification

Presence Sharing allows subscriptions and notifications of the willingness and ability of a user to communicate with other users on the network. This includes SIP presence agents and external presence systems.

• Allows using a specialized event package in compliance with the Common Profile for Presence (CPP).
• Supports presence state exchange between participants and external systems over TLS protocol.

Message Time-to-Live and Out-of-band Inspection

Message Expiration allows to configure optional Time-to-Live (TTL) for SIP requests forwarded to the data layer. After TTL has been exceeded, the message is discarded or sent to an expiry destination for further inspection.

• Prevents message flooding with SIP requests that no consumers have expressed their interest in.
• Allows offline processing and archival of messages arriving to configured expiry destinations.

Message Persistence for Guaranteed Delivery

Message Durability relies on a high-performance file journal pre-created to a fixed size and functioning in the append-only mode. When one journal file is full, persistence is automatically rolled over to the next one.

• Allows to survive planned or unexpected gateway restarts, and enables guaranteed message delivery.
• Supports Linux asynchronous IO, allowing to avoid explicit syncs to disk and improve performance.

Filter Expressions for Targeted Message Subscription

Subscription Selectors allow to enable delivery to the data layer only of those SIP requests whose header fields match the specified filter expressions. Other requests will be ignored or expire based on their TTL value.

• Supports dynamic filter expressions based on a subset of SQL-92 conditional expression syntax.
• Improves processing performance with optimized message delivery based on consumer interest.

Duplicate Message Filtering for Exactly-once Delivery

Duplicate Detection enables automatic filtering of the same message delivered multiple times in case of recipient failure, without any coded business logic. Messages with the same unique header value are ignored.

• Enables only-once delivery guarantee of SIP requests to the data layer, similar to XA transactions.
• Supports duplicate filtering with both in-memory and persistence based message delivery.

Delayed Redelivery and Dead-letter Processing

Message Redelivery allows to configure a delay prior to subsequent delivery attempt after recipient failure or transaction rollback. This gives the recipient some time to recover from any transient failures.

• Prevents network overloading and CPU over-utilization with infinite message delivery in quick succession.
• Allows to configure a dead-letter destination where messages are sent after a number of send failures.

Transport Layer Security for Media and Data Transfer

In-transit Encryption allows the gateway to both receive SIP requests from endpoints and forward the corresponding HTTP messages to consumers over TLS protocol. This maintains data confidentiality and user privacy.

• Supports SIP Secure (SIPS) protocol while receiving media control requests from user agents.
• Supports HTTP Secure (HTTPS) protocol while sending data messages to service consumers.