Application Example: Building An Open Source, Open Standard Softswitch
The following example consists of a high density PICMG® 2.16 chassis featuring 10 6U x 160mm slots:
- Slots 1 and 10 are dedicated to 6U, PICMG 2.16 10/100/1000 Ethernet switches (fabric boards).
- Slots 2 through 9 are PICMG 2.16-compliant node slots, each supporting a single 33MHz, 64-bit CompactPCI® bus segment and one contiguous PICMG 2.5 R1.0 H.110 bus.
- Slots 2 through 8 are CompactPCI peripheral slots, and slot 9 is a single board computer (SBC).
- Below slot 10 are two 3U x 160mm slots for redundant intelligent shelf managers (ISMs). The rear panel I/O section directly behind the midplane supports IEEE 1101.11-style and 6U x 80mm rear panel transition modules (RTMs) for all 10 6U slots and a single 6U RTM slot, which supports the redundant pair of ISMs.
- The V(I/O) plane can be configured for either 3.3V or 5V operation.
This application example shows how widely available, feature-rich, open source applications for telecommunication can be easily ported for use on Performance Technologies open standards-based hardware. This serves as a good basis for delivering finished platforms to end users. OEMs can use this type of approach to shorten development times, fill gaps in products or develop product proof of concepts. Because these platforms are built on open standards-based products, they can be migrated to future hardware platforms using tools such as Performance Technologies' NexusWare® Linux OS® and Development Environment software products.
What products do we provide in this application?
Media Gateway: A transition device for moving data from one network topology to another. In our definition it usually means IP to TDM and back. This can include vocoding or can treat the stream as raw. The media gateway translates between circuit-switched voice traffic and packet-based traffic. In this demonstration system we are using a MTN4200 PTMC voice processing mezzanine card for vocoding, mounted on top of a CPC324 TDM/IP Edge Processor which provides 24 TDM (T1 or E1) framers and a processor for providing stream control. The media gateway software stack is still in development, but is being derived from open source projects.
Media Gateway Controller: A device which runs the call control and application-level calling features in a server and supports easy software upgrades and expansion of features. It is also called the "call agent" which controls the media gateway and call routing to other devices or services such as media servers, streaming servers or signaling gateways. In this particular demonstration we are using a SBC to host Asterisk™ as a media gateway controller/call agent for SIP clients.
Signaling Gateway: This device convert and/or relay network SS7 call signaling between the circuit network and the packet backbone. In this particular demonstration, we are using the SG5600 Signaling Gateway Blade to provide SS7 to SIP signaling, in support of data streams routed out over the PSTN through the media gateway board.
Media Server: This is a device for storing and serving streams of data to a feature server, media gateway or media gateway controller. In this particular demonstration, we are using a PICMG 2.16 SBC to host the SNOM 4S Media Server application. The SNOM 4S Media Server provides XML access to audio streams such as voice mail and interactive voice response prompts to the media gateway controller.
NAT Filter/Session Border Controller: This is a device which provides NAT firewall traversal, QoS support and other services in the public network to support SIP applications. In this demonstration system, we are using a CPC5505 SBC to host the SNOM 4S NATF firewall application. This application provides reliable session routing through NAT transition points and billing information.
Intelligent Shelf Manager: This device uses an "out-of-band" Intelligent Peripheral Management Bus to communicate with all of the devices in the system regarding system health including processor temperatures, fan speeds, power supply health and other hardware status. These sensor readings can then be used to trigger alarms, send SNMP traps or respond with policy based actions such as power resetting a device. In this example we are using CPC7301 Intelligent Shelf Managers.
Network Management Console: This device provides monitoring and policy based control of applications in the demonstration system. In this particular demonstration we are using a PICMG 2.16 SBC to host the Nagios® open source network monitoring system. This system is designed to poll each application in the system and accept SNMP traps from all applications and the CPC7301 Intelligent Shelf Managers. The network management console also provides secure access, using SSH and VNC to the consoles of all the devices in the system.
