Open Architecture Computer Telephony Servers and Tools

VoIP PCI H.323 Gateway

For computer telephony developers and integrators who are seeking to implement conversation quality speech over IP networks, Aculab offers the VoIP PCI card. This standards based H.323 gateway offers up to 60 channels with low latency, all in a single PCI slot.
Unlike other VoIP cards Aculab's product offers: ease of use through a simple familiar API; scalability to build a single gateway with multiple cards; optimal use of channels; and fully specified performance characteristics.

Ease of use Aculab's VoIP gateway comes with a single API, which is just a small extension to the generic API that existing customers will be familiar with. For new users all that is required is to master a couple of API commands or function calls, it's that simple. The API provides easy control of the H.323 protocol stack, RTP packet handling and voice compression, from within a single interface. For new and active developers alike this makes it easy to leverage VoIP through existing applications, which can be ported from current platforms with minimal time and effort.

Scalability When an H.323 call is set up all of the RTP packet handling is carried out on the card, the data path is fully offloaded from the host processor. This means there is no contention for host processor power, as packets are not crossing the host PCI bus, and a true scalable architecture is achieved. Multiple cards can therefore be installed to form a single H.323 gateway. With no adverse loading to the host, and a specified minimal contribution to delay from the card, there is little impact on latency regardless of the number of cards used.

Optimal use of channels When every channel counts, it is good to know that Aculab's VoIP card has sufficient power to simultaneously handle all 60 channels using any supported codec: G.711; G.723.1; G.729A/B. There is a free allocation of any of the above codecs on a per channel basis ensuring full usage at all times.

Fully specified performance Aculab's technology has been designed to minimise factors that impact conversation quality including delay, echo, and background noise. This leads to a reduced "effort to listen" for users. The VoIP gateway is designed as a multiple class terminal to meet TIPHON quality of service ratings. A system using Aculab's card allows High/Best quality ratings to be achieved on a suitable LAN, and High quality ratings to be achieved on a suitable WAN. It is therefore possible to deploy an "out of the box" solution meeting high performance standards in a well-managed private network environment.

Flexible hardware The VoIP PCI card offers complete H.323 gateway functionality for either 30 or 60 channels, including dual redundant 10/100 Base-T LAN interfaces as well as optional single or dual E1/T1 telephone network interfaces using Aculab's worldwide range of protocols and approvals. If separate telephony interfaces are preferred, the H.100 CT bus may be employed.

Technical summary

Physical & enviornmental		VolP PCI H.323 gateway
Card format		PCI full length expansion card
Single card slot?		Yes
Computer bus type		PCI Universal (5V or 3V3), 32 bit
CT bus interconnection		H.100
Arbitrary matrix switching between all timeslots?		Yes
CT bus (H.100) loading factor		1
Bridged chassis backplane working?		Yes
EMC standard		Europe, FCC and Australia: Class 'B'
Safety standard		CB certificate to IEC 950, Australian, ACATS 001, UL/ CUL
Power consumption	Maximum in Watts	23W
	Maximum in Amps	4.6A
Operating enviornment	Temperature	0 to 60°C
	Humidity	0 to 70% RH non-condensing
	Altitude	0 to 2,500m
Storage enviornment	Temperature	-20°C to 70°C
Operating systems supported		Windows NT/2000
H.323 gateway functionality
Voice activity detection (VAD)		Yes
Comfort noise generation		Yes
DTMF carriage, detection and generation		Yes
Jitter buffer (adaptive)		Yes
Echo cancellation up to 32ms		Yes
Fast on-board RTP/ UDP / IP		Yes
Supplementary services (call transfer)		Contact us to discus requirements
Codecs supported		G.711; G.723.1: G.729 (A+B)
Protocols supported	Contact us to discuss additional requirements	H.323 Version 1 & 2
Multiple cards can form a single H.323 gateway		Yes
TIPHON quality ratings (as defined in TR 101 329 V2 1.1 (1999-06)
In suitable LAN	4 (Best)	Equivalent to PSTN; End to end delay <150ms; Call set-up <1.5 second
In suitable WAN	3 (high)	Similar to PSTN; End to end delay <250ms; Call set-up <4 seconds
Full speech processing		Not applicable - Prosody recommended
Packet network access support
LAN protocol		10 / 100Base-T Ethernet
LAN connectors		Dual RJ45
VoIP module		30 or 60 channels
Redundancy		Full dual port redundancy
Digital telephone network access support
Optional hardware module	PM1 or PM2 daughter module	2 E1 or T1 links, 60 channels
	Network connectors	1 or 2 off RJ45/RJ48C, BNC via adapter
	Network terminations	75R, 100R or 120R
Telecom approval	A wide range of host independent approvals have been achieved by Aculab. In many countries it is possible to obtain Host Independent type approval, such that the access card may be integrated into PC based solutions without further telecom approvals being required. In regions where this option is not available, each complete customer solution will need to be submitted for approval, and Aculab has experience in supporting integrators in gaining such system level type approvals. A summary table of the approvals and protocol information is available upon request. Please note that a number of protocols are used throughout the world, (like DPNSS, QSIG and SS7) and are indexed as "Worldwide" in the tables.
Protocols supported	A worldwide range of protocols coverage has been achieved including E1, T1, SS7 and many variants of CAS - see above for more information.

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