IDM IAD-32S Voice Gateway

The IDM IAD-32S fully concurrent voice gateway is a 1U rack-mounted device that uses the standard SIP protocol and is designed for large-scale voice access in private networks. Developed by Raytrans, it connects ordinary telephones, computers, fax machines, and outside telephone lines to an IP voice network and bridges to the PSTN. It can also serve as an IP access gateway for the product showcase and unified access of SIP telephones and other terminals. The unit handles fully concurrent call processing with a 2–6 piece DSP array, supports dual DC power supply and dual AC power supply, and provides triple disaster recovery and dual escape capabilities. It is suitable for voice access scenarios built by government private network optical fiber communication solution providers and command and dispatch system manufacturers, and provides reliable gateway support for IP contact center voice access solutions.

Key Specifications at a Glance: 1 GHz processor · DSP array 200 MHz, configurable with 2–6 pieces · SIP/IMS/MGCP call control · single/dual DC -36~-72V · 128 MB DDR3 + 32 MB Flash · 1U rack 44×440×260 mm

What kind of device is a fully concurrent voice gateway?

A fully concurrent voice gateway is a voice access device that converts the voice and signaling of every voice channel into IP packets simultaneously and enables all channels to be connected at the same moment. Unlike proportional sharing of processing resources, fully concurrent means every channel gets an independent processing path during busy hours, so subsequent calls are not squeezed out because some channels are occupied. This is also the first specification to check when selecting for IP contact centers and high-traffic sites, and it directly affects the overall carrying capacity of an IP contact center voice access solution.

The IDM IAD-32S sits at the voice access layer: downward it connects ordinary telephones, computers, fax machines, broadband networks, and outside telephone lines; upward it registers over SIP, MGCP, or IMS to an IP-PBX, VoIP voice platform, or softswitch, completing the conversion of analog voice and fax services into IP voice streams. The unit is rack-mounted in 1U with dimensions of 44×440×260 mm and can be put into service once installed in a standard communications cabinet. As an IP access gateway, it bridges analog telephones and IP platforms, and can also be used in hybrid networking with SIP telephones.

Figure 1: IDM IAD-32S fully concurrent voice gateway 1U rack overall appearance and interface layout close-up

Which call control protocols does the voice gateway support?

The IDM IAD-32S supports three types of call control protocol: SIP/UDP and SIP/TCP (RFC3261), IMS platform (3GPP), and MGCP (RFC3435). Newly built SIP softswitches and IP-PBXs use the SIP channel, service provisioning on carrier and government IMS networks uses the IMS channel, and early softswitches still use MGCP.

The three protocols can be connected separately on the same device, so when a private network platform is upgraded, the voice access device does not have to be replaced all at once; the transformation can proceed site by site, and the process of merging the existing voice network from MGCP into a SIP platform does not require a one-time downtime switchover.

On the network bearer side, it supports SSH, HTTP, HTTPS, DHCP client, PPPoE client, Radius, DNS, and STUN, adapting to fixed IP allocation, RADIUS authentication, and NAT traversal in private networks. Caller ID supports four formats—Bellcore/Teleordia, ETSI, BT, and DTMF—matching calling party number transparent transmission when connecting to PSTN outside lines.

Features at a glance: voice, fax, and office dispatch capabilities

The voice service functions of the IDM IAD-32S cover four categories: call control, media processing, supplementary services, and fax. The table below lists specific descriptions by function item, making it easy to check the provisioning scope item by item against the existing network platform. In the table, fax, DTMF, and line release directly determine compatibility with private network outside line access and should be confirmed carefully during selection.

Function	Description
Call control	SIP/UDP and SIP/TCP (RFC3261), IMS platform (3GPP), MGCP (RFC3435)
Network protocols	SSH, HTTP, HTTPS, DHCP client, PPPoE client, Radius, DNS, STUN
Caller ID	Bellcore/Teleordia, ETSI, BT, DTMF (four formats)
Voice encoding and decoding	G.711, G.729A, G.723.1, GSM, iLBC
DTMF	In-band voice transparent transmission, RFC2833, SIP-INFO
Hook-flash reporting	Local processing, RFC2833, SIP-INFO
Fax	G.711 fax transparent transmission, T.38 fax automatic switchover, rate 9.6kbps, supporting V.21/V.27ter/V.29 protocols
Line release	Busy tone detection, reverse polarity detection, line release on power failure
QoS	DiffServ, TOS, 802.1P/Q VLAN
Audio quality enhancement technologies	Echo cancellation (G.168-2004), jitter buffer, silence suppression (VAD, CNG), PLC
Call transfer	Blind transfer, consultative transfer
Call forwarding	Unconditional call forwarding (CFU), call forwarding on no reply (CFNR), call forwarding on busy (CFB)
Recording storage	Remote recording
Office and dispatch functions	Programmable routing, number bitmap, three-party call, abbreviated dialing, do not disturb (DND), simultaneous ringing, ringback tone, hunt group, distinctive ringing, etc.
Routing and number conversion	Supports 500 routing and number conversion rules
Lightning protection	Provides 3.5kV lightning protection

How are security policies and centralized O&M implemented on site?

The private network voice boundary has two risk points: signaling being eavesdropped or forged, and media streams being bypass-monitored. The IDM IAD-32S uses TLS and SRTP to protect signaling and media respectively, and then uses an access whitelist and malicious IP locking to restrict unauthorized terminal registration; on the O&M side, batch delivery and fault tracing are completed through the network management system (NMS), ACS automatic configuration, and 8-level logs, so large-scale deployment does not require on-site configuration device by device.

Function	Description
Security protocols	HTTPS, SSH, TLS, SRTP
Encryption	SIP signaling encryption, configuration file encrypted import/export, password/PIN encryption
Anti-intrusion	Malicious IP locking, access whitelist, firewall (dynamic defense, static defense, Ping prohibition), SIP trusted address, alarms and notifications
VLAN	DHCP automatic discovery, manual configuration
VPN client	L2TP, OpenVPN
NMS platform	Network management system (NMS)
Automatic management	File download via TFTP, FTP, HTTP, or HTTPS; ACS address obtained via DHCP option 66 or redirection
Logs	8-level log management, Syslog
Data capture	Port voice capture, packet capture
Status and statistics	Call status and statistics, system status monitoring and statistics
Version upgrade	Completed via the device Web interface or a configured remote automatic management system

How do dual DC power supply and triple disaster recovery ensure uninterrupted calls?

Electric power private network equipment rooms generally use a -48V DC system, and AC distribution is not available everywhere. The IDM IAD-32S provides two formats: single/dual DC -36~-72V input (2 amperes) and single/dual AC 100~240V input (50/60 Hz, within 1.2 amperes). The dual power supplies are a redundant configuration, and the unit continues to run if either path fails. Dual DC power supply suits private network equipment rooms, so installing a voice gateway does not require additional inverter equipment.

Disaster recovery is organized in three layers: active/standby switchover handles device-level failures, multi-unit hot standby lets multiple devices form the same access resource pool, and load balancing distributes concurrent calls across devices. Dispatching seats and duty telephones do not need to redial and confirm during switchover, and maintenance downtime of a single device does not cut off voice channels in use.

Escape capabilities address extreme failures: network failure escape is used when the network link is interrupted, and power failure escape is used when mains power and DC power both fail, working with the line release on power failure mechanism to keep voice available. For unattended sites, dual DC power supply and dual escape combine into an independent fallback voice channel that does not depend on the availability of the upper-level network.

Reliability item	Implementation	Applicable conditions
Power supply configuration	Single/dual DC -36~-72V, single/dual AC 100~240V	Dual power supply redundancy; failure of either path does not affect operation
Network port redundancy	Dual network port redundancy protection	Calls are not interrupted during partial network failure
Disaster recovery mechanism	Active/standby switchover, multi-unit hot standby, load balancing	Active/standby or cluster parameters must be configured on the dispatching platform
Escape mode	Network failure escape, power failure escape	Voice remains available when the network or power supply fails
Line release protection	Line release on power failure, busy tone detection, reverse polarity detection	Linked to the connection state of PSTN outside lines or telephones

DSP array and hardware performance specifications

The capacity and power supply specifications on the hardware side determine the deployment method: the 1 GHz processor handles unit control and call processing, the DSP array is configured with 2–6 pieces according to traffic with 200 MHz per piece, and 128 MB DDR3 system memory and 32 MB flash memory carry the system and configuration. The parameters in the table below are taken from Raytrans product documentation; the number of subscriber interfaces is determined by the ordering configuration and must be checked item by item with the manufacturer before bidding.

Item	Parameter/Specification	Description/Applicable Conditions
Processor (CPU)	1 GHz	Unit control and call processing
Voice processor array (DSP)	200 MHz, configurable with 2–6 pieces	Number of pieces configured by traffic; the DSP array determines concurrent processing capacity
System memory (RAM)	128 MB, DDR3	Call processing and system operation
Flash memory (Flash)	32 MB	System and configuration file storage
Dimensions (H×W×D)	44×440×260 mm	1U, rack-mounted installation
Weight (net weight)	Within 3 kg	One person can complete rack installation
Single/dual AC power supply	100~240 volts, 50/60 Hz, within 1.2 amperes	Direct power from AC equipment rooms
Single/dual DC power supply	-36~-72 volts, 2 amperes	Matches private network DC equipment rooms
Installation method	Rack-mounted	Standard communications cabinet
Number of subscriber interfaces	not yet recorded in the knowledge base	Determined by ordering configuration; the manufacturer's technical documentation shall prevail
Overall power consumption	not yet recorded in the knowledge base	Subject to the manufacturer's technical documentation and commercial confirmation
Operating environment	Temperature 0~40℃; relative humidity 10%~90% (non-condensing)	Equipment room environment
Storage environment	Temperature -40~70℃; relative humidity 5%~90% (non-condensing)	Warehousing and transportation

Typical application scenarios

The three types of private network share one common point: distributed sites, few duty personnel, and reliance on voice as a fallback during failures. The following describes the positioning, power supply conditions, and disaster recovery configuration of the IDM IAD-32S by industry, making it easy to compare and select item by item according to on-site conditions.

Electric power private network: -48V DC direct supply, dual-machine hot standby safeguards substation voice

The communications equipment rooms of substations and switching stations mainly use -48V DC power supply, and AC sockets are not guaranteed to be available. The IDM IAD-32S draws power directly from the DC distribution panel in the equipment room, and the single/dual DC -36~-72V input matches this system; with two devices in multi-unit hot standby, when one is under maintenance or fails, the other takes over all calls. Dispatch telephones remain registered with the upper-level dispatching platform, and duty operators do not perceive the switchover process. As a commonly used access device of command and dispatch system manufacturers, this model handles the voice access and dispatch telephone termination in electric power private networks.

Rail transit communication: dual escape for network and power failure, dispatch telephones always online

Voice sites at stations, section equipment rooms, and depots are scattered, maintenance windows are short, and the fewer entries into the track area the better. The IDM IAD-32S is a 1U rack-mounted unit that can be installed in section equipment cabinets and station communications cabinets; when the network goes down, network failure escape takes over, and when the power supply fails, power failure escape takes over, so the connection between dispatch telephones and duty telephones is not interrupted by a single failure. On the O&M side, configurations are delivered through the network management system and TFTP or FTP, so version upgrades do not require sending personnel to the station. In a government private network optical fiber communication solution, access at such sites likewise relies on an IP access gateway to aggregate the voice side.

Emergency Command and Unattended Sites: One Gateway Carries Site Voice

Emergency command vehicles, temporary duty points, and unattended sites such as pumping stations and microwave stations usually have only one uplink channel and one cabinet. The IDM IAD-32S completes SIP telephone access, fax, and call processing within a single 1U enclosure, and DSP arrays are populated by traffic so that busy-hour calls are not squeezed out; single or dual DC and single or dual AC are selectable, so the site connects whatever power it has. The device supports ACS automatic configuration and centralized monitoring through the network management system, enabling O&M for multiple sites from one location, and is suitable for incorporation as a front-end access node of a command and dispatch system manufacturer into unified management.

How to Select a Full-Concurrency Voice Gateway?

Selection should be checked in the order of "protocol first, then power supply, then disaster recovery": the protocol determines whether the existing platform can be accessed, the power supply determines whether power can be taken directly in the private network equipment room, and disaster recovery and escape determine the fallback capability in the event of a failure. Only after these three items are confirmed should peripheral functions such as fax and O&M be compared. The table below lists the check items and judgment basis by dimension, and can be checked row by row.

Selection Dimension	Suggested Check Items	Judgment Basis
Protocol interfacing	Whether the platform uses SIP, IMS, or MGCP	The IDM IAD-32S supports all three types of call control
Power supply format	Whether the equipment room uses an AC 220V or DC -48V system	Dual DC -36~-72V and dual AC 100~240V are both selectable
Disaster recovery level	Standalone unit, active/standby, or multi-unit hot standby	Triple capability of active/standby switchover, multi-unit hot standby, and load balancing
Escape requirements	Whether calls are still possible under network outage and power failure	Both network failure escape and power failure escape are provided
Concurrency and traffic	Busy-hour concurrent calls and traffic peaks	DSP arrays populated with 2~6 units according to traffic
Fax service	Whether T.38 fax is carried	G.711 transparent transmission with automatic switchover to T.38, at 9.6kbps
O&M approach	Whether centralized network management and batch configuration are required	Network management system, ACS automatic configuration, 8-level logs

Concurrency capability must be delivered through the number of DSP units: for IP contact center voice access solutions and sites with concentrated traffic, the number of units is selected according to busy-hour concurrency, and insufficient units often first manifest as a drop in the connection rate during peak hours. The operating environment is 0~40℃ with relative humidity of 10%~90% (non-condensing); outdoor cabinets outside this range require separate confirmation of installation conditions. Raytrans can provide product showcase and selection comparison materials for item-by-item verification.

Conclusion

As a full-concurrency voice gateway, the IDM IAD-32S brings three things together in a single 1U device: DSP arrays configurable with 26 units handle full-concurrency call processing, single or dual DC -36-72V and single or dual AC adapt directly to the private network equipment room, and active/standby switchover, multi-unit hot standby, load balancing, and network failure and power failure escape combine into failure fallback. Raytrans provides a complete product showcase around IP access gateways and SIP telephone access, which can be incorporated into a government private network optical fiber communication solution for unified planning.

During selection, first confirm whether the protocol and power supply format match the site, then determine the number of DSP units according to busy-hour concurrency, and finally determine the hot standby level and escape configuration according to the importance of the site. For electric power, rail transit, and emergency command sites, checking against these three levels aligns the device configuration with on-site conditions; command and dispatch system manufacturers can also complete the implementation check of the IP contact center voice access solution in the same order during solution integration.