IDM IAD-EX4O Lightning-Protected IP Telephone Exchange

IDM IAD-EX4O is a new-generation 64ms echo cancellation IP telephone exchange developed by Raytrans. As an IP access gateway designed for multi-industry scenarios, it is used to uniformly connect analog telephones, fax machines, and computer softphones at the site side to the IP voice network, supports carrier IMS access, and integrates telephone, fax, recording, customer management, and mobile extensions.

IDM IAD-EX4O provides 24 built-in analog ports, 20 IP outside line licenses, and 20 concurrent agent clients in a standalone unit, and can carry the voice switching and dispatch of an entire work site. The device features built-in G.168-2004 echo cancellation (64ms tail length) and T.38 fax, making it suitable for long-distance link scenarios such as electric power and energy private networks, rail transit communication, and unattended field sites. With this product, Raytrans provides stable and reliable voice access capabilities for command and dispatch system manufacturers, government private network optical fiber communication solutions, military emergency communications vehicle solutions, and smart mining communication solutions, and can work with SIP telephones and intrinsically safe mining communication terminals to complete end-to-end product showcase and deployment verification.

Key Specifications at a Glance: 24 analog ports · 20 IP outside line licenses · 20 concurrent agent clients · 24 simultaneous calls (with recording) · 64ms echo cancellation (G.168-2004) · T.38 fax 33.6kbps (G3 compatible) · 3.5kV lightning protection


What Kind of Device Is a 64ms Echo Cancellation IP Telephone Exchange?

A 64ms echo cancellation IP telephone exchange is an integrated switching device that converts analog telephone resources at the site side into IP voice services. It assumes the extension and trunk functions of a traditional SPC exchange and accesses carrier IMS platforms or proprietary IP voice platforms through SIP and MGCP protocols. As a typical IP access gateway, IDM IAD-EX4O uses SIP/UDP and SIP/TCP (RFC3261), IMS platform (3GPP), and MGCP (RFC3435) as call control protocols, and can interface with carrier IMS networks, IP-PBX, and third-party softswitch platforms, making it directly deployable in both office environments and industrial private networks.

In terms of access capacity, IDM IAD-EX4O provides a 20-user capacity, 24 built-in analog ports, 4 IP extension licenses, and 20 IP outside line licenses, and supports concurrent login of computer agent clients within the local area network. Voice codecs cover G.711 (a/u), G.729B, G.722.2, and G.722. Caller ID supports multiple standards including Bellcore Type 1&2, ETSI, BT, NTT, and DTMF. DTMF transmission supports three methods: in-band voice transmission, RFC2833, and SIP-INFO.

In terms of network access and remote management, IDM IAD-EX4O supports Telnet, SSH, HTTP, and HTTPS management channels, and provides DHCP client, PPPoE client, DNS, STUN, OpenVPN client, and 802.1X capabilities, enabling cross-public-network access to private networks, branch networking, and mobile office. Fax services support G.711 transparent transmission and T.38 fax, are compatible with G3 fax machines, and operate at 33.6kbps (transparent transmission/T.38 V3).

Core Functions and Performance Specifications

IDM IAD-EX4O integrates protocol intercommunication, network access, media processing, and voice optimization into a single device. The functions are listed by category in the table below, and performance specifications are subject to the manufacturer's technical documentation and commercial confirmation.

Category	Function	Description
Protocol	Call control	SIP/UDP and SIP/TCP (RFC3261), IMS platform (3GPP), MGCP (RFC3435)
Network	Access and management	Telnet, SSH, HTTP, HTTPS, DHCP client, PPPoE client, DNS, STUN, OpenVPN client, 802.1X
Media	Caller ID	Bellcore Type 1&2, ETSI, BT, NTT, DTMF multiple caller ID standards
Media	Voice codec	G.711 (a/u), G.729B, G.722.2, G.722
Media	DTMF transmission	In-band voice transmission, RFC2833, SIP-INFO
Media	Fax	G.711 transparent transmission, T.38 fax, G3 fax machine compatible, 33.6kbps (transparent transmission/T.38 V3)
Voice	Line release	Busy tone detection, reverse polarity detection, line release on power failure
Voice	Voice quality enhancement	Echo cancellation (G.168-2004, 64ms tail length), automatic jitter buffer adjustment

Item	Parameter/Specification	Description/Applicable Conditions
User capacity	20	Maximum number of users registrable on a standalone unit
Built-in analog ports	24	Directly connect ordinary telephones, fax machines, and other analog terminals
IP extension licenses	4	Remote IP telephone and softphone registration
IP outside line licenses	20	Access carrier IMS or IP-PBX outside lines
Number of simultaneous calls (with recording)	24	Concurrent channels for calls with full recording
Concurrent agent clients	20	Concurrent login of computer agent clients
Echo cancellation	G.168-2004, 64ms tail length	For long-distance links and cross-network calls
Lightning protection	3.5kV	Built into power and voice interface sides
Processor/Memory/Flash	Dual-core 860MHz / 256MB / 16MB	Voice processing and program storage
Built-in storage	16GB	Local recording retention, caching during network outage
Power supply	12VDC/1.5A	Powered by adapter included in the package
Power consumption	9W	Overall power consumption
Installation method	Desktop/rack-mounted	Desktop placement or cabinet installation
Operating environment	0~40℃, 10%~90% (non-condensing)	Indoor and protected cabinet environments
Storage environment	-40~70℃, 5%~90% (non-condensing)	Transportation and storage conditions

How 24 Analog Ports and 20 IP Outside Lines Carry Private Network Dispatch on a Single Device

The capacity bottleneck of private network dispatch usually lies in the number of analog ports and outside lines: if site telephones cannot all be connected and outside lines are insufficient, multiple voice devices must be stacked. With 24 analog ports plus 20 IP outside line licenses, 20 concurrent agent clients, and 24 simultaneous calls with recording, IDM IAD-EX4O covers all voice switching needs of a small-to-medium site with a single device. For command and dispatch system manufacturers, this type of IP access gateway effectively simplifies system layers, and with SIP telephones, a dispatch call handling system can be quickly set up.

The 24 analog ports can directly connect ordinary telephones, fax machines, and dispatch telephones. The 20 IP outside lines are used to interface with carrier IMS or existing IP-PBX. Agent clients log in concurrently as softphones within the local area network. Extensions, outside lines, and agent seats—three types of resources—complete switching and recording within the same device, reducing cabinet space and spare parts simultaneously. Such devices provided by Raytrans can be flexibly embedded into government private network optical fiber communication solutions, military emergency communications vehicle solutions, and smart mining communication solutions as core nodes of the voice access layer.

In terms of reliability details, IDM IAD-EX4O supports three line release methods: busy tone detection, reverse polarity detection, and line release on power failure. With 8-level log management and Syslog, unattended sites can quickly recover and trace back during power failure or link interruption. Port voice capture and packet capture can be used for call review and fault location.

How to Solve Voice Echo on Long-Distance Field Links: G.168-2004 Echo Cancellation

Echo is a typical problem of long-distance voice links: the four-wire to two-wire conversion point generates impedance mismatch echoes. The longer the link and the more cross-network segments, the later the echo returns, and the more it sounds like "echo." The core specification for solving this is the tail length of the echo canceller—the longer the tail length, the more margin for suppressing echo paths.

IDM IAD-EX4O uses G.168-2004 standard echo cancellation with a 64ms tail length and features automatic jitter buffer adjustment. The 64ms tail window is sufficient to cover echo delay generated when field sites backhaul through optical multiplexers, microwave, or public network links, keeping voice clear without dropped syllables on long-distance links. In military emergency communications vehicle solutions and smart mining communication solutions, field links are often complex, and this echo cancellation capability ensures call quality of the IP access gateway in long-distance backhaul scenarios. Intrinsically safe mining communication equipment from Raytrans can also benefit from this voice optimization mechanism.

How to Configure T.38 Fax Without Dropping the Line

Fax is prone to speed reduction and page drops on IP links, rooted in voice codec compression and packet loss. IDM IAD-EX4O supports both G.711 transparent transmission and T.38 fax: T.38 converts T.30 fax signaling and image data into IP-side data packets, bypassing distortion caused by voice compression, so G3 fax machines can send and receive stably at 33.6kbps over private networks. Whether interfacing with SIP telephones or dispatch console terminals, fax services can run in parallel with voice services on the same IP access gateway.

During deployment, it is recommended to fix the codec of the voice channel where the fax port resides to G.711 and confirm that both devices have T.38 enabled. If there is a firewall or NAT on the link, the media ports associated with T.38 need to be opened to avoid interruption of fax negotiation. In government private network optical fiber communication solutions, Raytrans can combine intrinsically safe mining communication equipment and IP access gateways for unified deployment, meeting voice and fax requirements in multiple scenarios.

Typical Application Scenarios

Electric Power and Energy Private Network Substation Dispatch

Dispatch telephones, maintenance telephones, and faxes at substations and energy sites need to be online for long periods, and many sites are located in outdoor environments where lightning strikes and induced overvoltage occur frequently. As an IP access gateway for private network scenarios, IDM IAD-EX4O provides 3.5kV lightning protection. Its 24 analog ports can directly connect dispatch telephones and fax machines, and its 20 IP outside lines connect to carrier IMS or electric power private network IP-PBX, achieving unified bearing of dispatch and office voice. The device supports network management systems and third-party network management (TR-069, SNMP), enabling remote configuration and alarm handling from the prefecture-level side.


Rail Transit Communication and Pipe Gallery Equipment Rooms

Rail transit station sections and integrated pipe gallery equipment rooms have tight rack positions and limited inspection windows, so voice devices need to be small, low-power, and easy to maintain remotely. IDM IAD-EX4O is dual-use for desktop and rack mounting, with overall power consumption of 9W, suitable for embedding into existing cabinets. It supports plug-and-play rapid deployment of IP telephones and can interface with monitoring, alarm, and dispatch platforms. Voice extensions, section telephones, and fax services at the equipment room side are carried by a single device. The device supports traversal service and open API interfaces for easy linkage with third-party application systems.

Voice Access at Unattended Field Sites

Unattended field sites usually have no equipment room shielding or permanent O&M personnel, and lightning strikes, power supply fluctuations, and link interruptions are the norm. The 3.5kV lightning protection, line release on power failure, and reverse polarity detection capabilities of IDM IAD-EX4O can preserve voice channels and enable rapid recovery under abnormal conditions. The built-in 16GB storage allows call recordings to be retained locally during network outage, and 24 concurrent calls with recording can fully record dispatch and safety calls, providing evidence for later verification.


How to Select an IP Telephone Exchange: First Look at Analog Ports, IP Outside Lines, and Concurrency

Selection starts with a clear count of on-site resources: the number of analog telephones and fax machines determines the required built-in analog ports, the outside line access mode determines the number of IP outside line licenses, and the number of agent seats determines the number of concurrent clients. With 24 analog ports, 20 IP outside lines, and 20 concurrent agent seats, the IDM IAD-EX4O covers small and medium-sized sites with a user capacity of up to 20.

Selection Dimension	IDM IAD-EX4O Configuration	Description
Number of analog telephones and fax machines	24 built-in analog ports	A standalone unit covers sites with up to 20 users
Outside line access mode	20 IP outside line licenses, supporting IMS and IP-PBX	Interconnects with both carrier outside lines and private network outside lines
Agent seats and call concurrency	20 concurrent agent clients, 24 concurrent calls with recording	No capacity expansion needed for call-intensive sites
Call quality requirements	Echo cancellation G.168-2004, tail length 64ms	For long-distance links and cross-network calls
Fax service	T.38 fax, compatible with G3 fax machines, rate 33.6kbps	Private network fax does not go down or drop speed
Deployment environment	3.5kV lightning protection, desktop/rack-mounted, power consumption 9W	Field sites and unattended equipment rooms
O&M approach	Network management system and third-party network management (TR-069, SNMP)	Remote O&M for unattended sites

Next, confirm the protocol and security requirements: during selection, check whether carrier IMS, common codecs such as G.711/G.729, and T.38 fax are supported, and confirm whether capabilities such as signaling and media encryption, anti-intrusion, and access whitelist are complete. Finally, consider the deployment environment: for field and outdoor sites, give priority to lightning protection level and remote O&M capability to avoid frequent on-site maintenance later.