Carrier-grade Media Server for SIP and IMS networks
Telco / Service Delivery Platform
The Media Server combines classic carrier media functions with modern speech and AI processing, integrates existing media resources and allows a step-by-step, scalable modernisation of voice services.
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At a glance
Role, tasks, benefits and integration.
Solution
The SIP-based Media Resource Function within the CreaLog SDP. It provides dedicated media functions for IMS and SIP-based networks.
Task
Announcements, early media, DTMF detection, IVR menus, audio and video streaming, voicemail and call recording. Speech recognition, text-to-speech and LLM integration. Provision of real-time text (RTT).
Benefits
Provide media resources under control, keep using existing media platforms, add new capacity and modernise voice services step by step.
Integration
The SIP Application Server includes the Media Resource Function (MRF) to suit the respective service, supporting MSML, VoiceXML and NetAnn, early media and more.
Media functions for interactive voice services
The Media Server forms the media layer of the CreaLog Service Delivery Platform. It processes RTP media streams and provides the media resources that interactive voice services need in telco networks. The SIP Application Server controls the flow and selects the appropriate media resource. The Media Resource Server executes the respective media function – playing an announcement, detecting DTMF input, supporting a dialogue or starting a recording, for example. The CreaLog MRF supports, among other things:
Announcements and tones
- Announcements and tariff information
- Early media before a call is answered
- Ringback, warning and notification tones
Recording
- Voicemail recording
- Call recording
- Audio and video streaming
Speech processing
- Speech synthesis via text-to-speech
- Speech recognition
- Media processing for AI agents
Extending classic services with AI
Modern voice services increasingly combine proven telco functions with speech recognition and AI.
The CreaLog MRF provides the media layer required for this. Voice data can be recorded, played back or handed to suitable speech and AI components.
Classic IVR and voicemail services can be extended, for example, with:
natural voicebot dialogue
multilingual speech output
voicemail transcription
automatic call notes
translation and summarisation
voice-based pre-qualification
AI-assisted routing support
Service control, AI logic and backend integration remain in the platform components intended for them. The MRF concentrates on reliable media processing.
Media Server in operation
Technical positioning and integration
In distributed architectures, several SIP Application Servers and MRF instances can work together. The state and load of the available media resources are monitored. The SIP Application Server can select a suitable MRF instance based on criteria such as priority, availability and current channel usage. It addresses the instance via NetAnn, MSML, VXML or proprietary protocols. External or existing MRF and media server systems can also be integrated. Supported audio codecs are G.711, G.726, G.722, EVS, AMR-WB and AMR-NB, plus T.30/T.38 for fax and T.140/RED for real-time text.
Operation, monitoring and scaling
Several SIP Application Servers work together with several MRF instances across sites. Instances are selected dynamically by priority, availability and channel usage.
Discuss the Media Resource Function
We will demonstrate the concrete implementation with a use case.
