Far South NetworksA Journey in Technology

From Asterisk to CommaWhen Far South Networks began developing its product range in 2006, Asterisk® was already making its presence felt for its unmatched ability to bridge the legacy PSTN world with the emerging VoIP ecosystem.

We realized there was an opportunity for a telephony product that could leverage the rapidly escalating MIPS per dollar of commodity servers, while providing solid PSTN connectivity.

In 2008 the Comma iTA was introduced into the South African market, and quickly achieved success in applications from small business PBX to large multi-tenant analog installations with hundreds of endpoints.

www.farsouthnet.comCopyright © 2007-2013 Far South Networks (Pty) Ltd

Far South Networks is a manufacturer of innovative telephony products based on high quality, purpose-built hardware platforms and Open Source-based software.

Far South Networks is based in Cape Town, South Africa.

At left is a Comma iTA pictured with a Commodity Server.

The unit shown has 32 analog ports, 8 ISDN BRA ports and 1 ISDN PRA port.

We have supplied installations with up to 20 Comma iTAs connected to a single Asterisk instance.

There are also PRI installations with up to 12 PRA interfaces.

Comma iTA - Designed for Asterisk®

Far South NetworksA Journey in Technology

Comma Architecture – Simply InnovativeComma SoC – the Comma iTA was developed using a fresh architecture based around an FPGA as the SoC. A 32-bit soft processor (Altera Nios II) and peripherals were combined with in-house developed IP cores, most notably:

T1/E1 Framer – standards-compliant framer for T1 and E1, with built-in TDM to memory packet back-end.

TBR4 compliance (TUV Rheinland) was achieved in 2010 in conjunction with libpri. and Asterisk.

Hardware Echo Canceller – IP core capable of processing 64 channels at 128 taps (16ms), or 32 channels at 512 taps (64ms). Uses a dual cache of per-channel samples and context data, with a DMA engine to swap in/out from system memory, and multiple parallel signal processing elements: FIR for echo estimation, LMS for adaptive coefficient update, and dedicated parameter calculation and update engine.

Digital PLL – software-assisted clock adaptation allows synchronization to PSTN (ISDN BRA/PRA) or to Ethernet TDMoE frames.

To achieve the highly scalable, yet conceptually simple Comma Architecture, we had to invent a little bit, without re-inventing the wheel:

ISDNoIP – add-on driver to mISDN stack encapsulates ISDN B- and D-channels in UDP frames, allowing scalable expansion to many ISDN BRA ports in packet-over-Ethernet architecture.

TBR3 compliance (TUV Rheinland) was achieved in 2009 with the Comma iTA, ISDNoIP, mISDN and Asterisk.

Comma Management Protocol – this DHCP-based protocol allows Comma iTA devices to be discovered, booted and managed using a platform-independent, Python-based manager on the host server.

www.farsouthnet.comCopyright © 2007-2013 Far South Networks (Pty) Ltd

D-TC

I-TC

TDM I/O S

SDRAMController

S

I-cache

M

Nios II/f

D-cache

EchoCancellerEngine S

EPCSController

S

OpencoresEthernet

MAC

S

MTo TDM

Highways

100 Base-TPHY

SDRAM32-bit100 MHz

SPI Flash

SPIController

STo ExpansionCards

Nios II I-Bus

Nios II D-Bus

Ethernet MAC Master Bus

ECE DMA Master Bus

Instruction/Data

DPRAM

S

S

M

M

M

GPIOS To Board I/O

To T1/E1LIU

M

T1/E1Framer

S

SDRAMPerf. Mon.

S

Timer

JTAG UART S

S

Far South Networks SOPC Components

Altera SOPC Components

Open Source SOPC Components

Avalon Bus Fabric

Sample CacheCoefficient

Cache

MAC

X +

X-law tolinear

Linear tox-law

Leaky LMS

X +

Context CacheDMA

ControllerChannel

Scheduler

MAC

X +

Leaky LMS

X +

+ +|x|

x2

1/x

Calculation MachineParallel FIR/LMS Machine

Avalon Master/Slave Interface

>

LPF Short LPF Long

HPF

Far South NetworksA Journey in Technology

Putting it All TogetherWe started out selling our Comma iTA hardware to Asterisk System Integrators, providing a set of Open Source drivers and the necessary technical support, and indeed the Comma iTA is still available as a standalone PSTN adapter. However, there was a clear market demand for an integrated device for SMB PBX and VoIP Gateway applications. We quickly responded with the

Com.X range of products.

On the hardware level, the Com.X1 and Com.X10 were built by a simple integration of Comma iTA hardware with an off-the-shelf x86-based Network Appliance, Solid-State Drive and accessories in a 1U enclosure.

For the software, we selected Ubuntu Linux, Asterisk and FreePBX as the base Open Source platform. We then designed a rich, wizard-like web GUI using Java and Google Web Toolkit, in order to simplify the configuration tasks as far as possible. The GUI abstracts the FreePBX interface to a simple, list/object/form based view, with full desktop style integration (menus, double clicks, right clicks, etc.) We also designed in additional major features such as SIP phone auto-provisioning, custom dialplan routing (FlexPath) and Integrated Access Device configuration – networking, firewall, PPPoE, VLAN, etc.

The Com.X software scales from small systems of 4, 8 or 16 extensions right up to systems with hundreds of extensions and many PSTN and SIP trunks.

www.farsouthnet.comCopyright © 2007-2013 Far South Networks (Pty) Ltd

Far South NetworksA Journey in Technology

Far South Networks Heads North – MPX and Com.X5The market received the Com.X products with much enthusiasm, so we embarked on a ground-up new design for the embedded server. We chose the Intel® Atom E6xx SoC processor and integrated our own hardware IP to provide on-board telephony. We also added 4 Gigabit Ethernet ports, USB, SDIO and SATA interfaces, a mini PCIe slot for wireless integration, and an optional on-board Li-Ion

UPS. We named the server board MPX “Media Processor Extreme”.

We were able to leverage our existing IP by placing the Hardware Echo Canceller and other telephony related functions into an Altera FPGA with PCIe interface to the processor. We retained the TDM interconnect from the Comma iTA, allowing re-use of all of our existing PSTN interface modules.

Using Intel's Boot Loader Development Kit, we developed a UEFI-based boot solution, supporting boot from network, USB, SDIO and SATA.

The MPX is equipped with 512MB on-board RAM and is available in 0.6GHz and 1.3GHz versions. It operates off a single 12VDC supply at less than 10W total power.

The Com.X5 PBX and Gateway range based on the MPX has sold thousands of units in the home market of South Africa, and is also being sold in other African markets. A new, plastic-packaged PBX appliance code-named “BlueBox” is currently under development.

www.farsouthnet.comCopyright © 2007-2013 Far South Networks (Pty) Ltd

Com.X5 Product Specification Fully Integrated VoIP PBX/Gateway with full Asterisk/FreePBX feature setVoIP trunks: Up to 16 x G.729Up to 8 Basic-Rate ISDN and 16 Analog FXS/FXO ports built-inUp to 50 user extensionsAdditional ports with Comma iTAs4 x 1000Base-T LAN16GB SD Card or 64GB SSDUbuntu 10.04, Asterisk 1.8Optional ADSL2+, X.21 Sync. SerialRoadmap FeaturesDECT – 6 handsets, 4 channels3G/LTE, WiFi

“BlueBox” MPX-Based Concept

Com.X5 Half-Rack PBX

Com.X5 Full-Rack PBX