IDM MAG-2E1 Digital Trunk Gateway IDM MAG-2E1 Digital Trunk Gateway

IDM MAG-2E1 digital trunk gateway is an IP access gateway developed by Beijing Ruiguang Jiyuan Digital Technology Co., Ltd. It uses a 1U rack-mounted design and performs call protocol conversion and media stream intercommunication between the IMS/SIP softswitch side and the ISDN PRI trunk of an existing SPC exchange (PBX). As an IP access gateway under Raytrans, the IDM MAG-2E1 E1 digital trunk gateway provides 1 to 4 E1/T1 interfaces, 120 concurrent calls at full configuration, and 512 SIP trunk account registrations. Through 4 adaptive 10/100/1000 Base-T network ports, it connects to a SIP softswitch, IMS platform, or IP-PBX, bringing traditional trunk telephone services and IP voice services onto the same communication network. The device supports dual network ports, dual power supply redundancy, and -36 to -72V DC power supply. Its 1U rack structure carries service aggregation in private network equipment rooms for electric power/energy, rail transit, and military/government sectors through high-density trunk access, and can be flexibly embedded in scenarios such as government private network optical fiber communication solutions, military emergency communications vehicle solutions, and smart mining communication solutions.

Key Specifications at a Glance: 4 E1/T1 ports · 120 concurrent calls at full configuration · SIP/UDP and SIP/TCP · ISDN PRI (30 B+D) and T1 23B+D · dual network ports and dual power supply redundancy · -36 to -72V DC · 1U rack · overall power consumption 18W


As a professional optical multiplexer manufacturer and command and dispatch system manufacturer, Raytrans provides a complete product showcase and technical support system for the IDM MAG-2E1 digital trunk gateway. This IP access gateway can be widely used in private network communication environments such as government private network optical fiber communication solutions, military emergency communications vehicle solutions, and smart mining communication solutions.

What Kind of Device Is the IDM MAG-2E1 E1 Digital Trunk Gateway?

An E1 digital trunk gateway is a protocol conversion and media processing device located between the trunk side of a PSTN or SPC exchange and an IP voice network. One side connects to an E1/T1 PRI trunk, and the other side registers with a softswitch, IMS platform, or IP-PBX over SIP. The IDM MAG-2E1 digital trunk gateway converts call protocols between IMS/SIP and ISDN PRI (30 B+D) through its network ports and E1/T1 interfaces. It is used for the connection between next-generation IP voice service networks and enterprise-side traditional SPC exchanges (PBX), and also for connecting enterprise IP voice switches (IP-PBX) to the traditional PSTN.

The IDM MAG-2E1 E1 digital trunk gateway has an overall processing capacity of 6000MIPS. Even at 120 concurrent calls, it can still perform voice processing (G.711/G.729A/G.723.1), echo cancellation, and T.38 fax relay. A single 1U device can handle the trunk access and aggregation of a medium-sized private network. As a professional IP access gateway, the device uses a 1U rack-mounted structure of 44×440×300mm. Its physical interfaces include 4 E1/T1 interfaces, 4 gigabit adaptive RJ45 network ports, 1 SD card interface, and 1 RJ45 configuration port (CON). It has 512MB system memory and 64MB flash memory.

The trunk side and IP side of an E1 digital trunk gateway are independent of one another in terms of alarms and maintenance: the IDM MAG-2E1 E1 digital trunk gateway provides bit error rate (BER) tests on ISDN links, local loopback, and B/D channel status queries. Trunk failures can be located at three levels—link, time slot, and call—without segment-by-segment troubleshooting using external instruments.

Which Call Control Protocols and Voice Codecs Does This Trunk Gateway Support?

The call control of the IDM MAG-2E1 E1 digital trunk gateway supports both SIP/UDP and SIP/TCP bearer modes, and supports IMS platform interconnection based on 3GPP specifications. Voice encoding and decoding covers five algorithms: G.711, G.729A, G.723.1, GSM, and iLBC. The table below summarizes the protocol and media processing capabilities. During selection, determine the codec combination based on the peer softswitch platform type and link bandwidth conditions.

Item	Protocol/Algorithm	Description
Call control	SIP/UDP, SIP/TCP (RFC3261), IMS platform (3GPP)	Interconnection with SIP softswitch and IMS platform
Network protocols	Telnet, SSH, HTTP, HTTPS, DHCP client, PPPoE client, DNS, STUN	Supports PPPoE dialing and registration in NAT environments
Voice encoding and decoding	G.711, G.729A, G.723.1, GSM, iLBC	Selected according to bandwidth and voice quality requirements
Fax	G.711 transparent transmission fax, T.38 fax, compatible with G3 fax machines, transparent transmission rate up to 33.6kbps	T.38 is recommended when fax traffic is heavy
Voice quality enhancement	Echo cancellation (G.168-2004), jitter buffer, silence suppression (VAD/CNG), PLC	Suppresses echo and packet loss effects in long-distance calls
Media proxy	Media stream RTP packet forwarding, firewall traversal, NAT traversal	Media streams do not pass through third-party relay
Signaling	E1 ISDN PRI (30 B+D), T1 ISDN PRI (23 B+D, ANSI NI-2)	Switch type compatible with 5ESS series and DMS series
DTMF	In-band voice transmission, RFC2833, SIP-INFO	Supports secondary dialing for attendant console and IVR
QoS	DiffServ, TOS, 802.1P/Q VLAN	Voice VLAN and priority marking

The interface characteristics of the E1 trunk side follow ITU-T G.703/G.704 recommendations. A single E1 link rate is 2.048Mbps with HDB3 line encoding. The D-channel signaling of ISDN PRI follows ITU-T Q.921/Q.931 recommendations. In E1 format, it is 30 B channels plus 1 D channel (30 B+D); in T1 format, it is 23B+D.

What Are the Core Functions of This Trunk Gateway?

The functions of the IDM MAG-2E1 E1 digital trunk gateway can be divided into five categories: trunk access, voice processing, registration and routing, security protection, and O&M management. All five categories are enabled simultaneously within the same 1U device, without the need for external trunk boards or protocol conversion servers. The function items and their descriptions are shown in the table below.

Function	Description
Trunk access	Provides 1 to 4 E1/T1 interfaces, supports E1 ISDN PRI (30 B+D, Chinese standard) and T1 ISDN PRI (23 B+D, ANSI NI-2 North American standard), switch type compatible with 5ESS series and DMS series
Call control	Supports SIP/UDP, SIP/TCP (RFC3261), and IMS platform (3GPP), performs call protocol conversion between IMS/SIP and ISDN PRI
Voice encoding and decoding	Supports G.711, G.729A, G.723.1, GSM, iLBC, and can negotiate codecs based on peer capabilities
Fax processing	Supports G.711 transparent transmission fax and T.38 fax, compatible with G3 fax machines, transparent transmission rate up to 33.6kbps
Voice quality enhancement	Echo cancellation (G.168-2004), jitter buffer, silence suppression (VAD/CNG), PLC packet loss compensation
Media proxy	Media stream RTP packet forwarding, firewall traversal, NAT traversal
Registration and authentication	Supports gateway registration and authentication, 512 SIP trunk account registrations
Number and routing	Number conversion, call routing (500 entries), number bitmap, RADIUS billing interface
QoS guarantee	DiffServ, TOS, 802.1P/Q VLAN marking
Security protection	HTTPS, SSH, TLS, SRTP; SIP signaling encryption and media stream encryption; configuration file encrypted import/export, password encryption; access whitelist, Ping prohibition, SIP trusted address
Port customization	SIP port, HTTP/HTTPS access port, and RTP port can be customized
Redundancy protection	Dual network ports, dual power supply redundancy protection; disaster recovery mechanism for active/standby SIP server switchover
Automatic management	Supports file download via TFTP, FTP, HTTP, or HTTPS; obtains ACS address via DHCP option 66 or redirection
Maintenance and diagnostics	8-level log management, Syslog; port voice capture and packet capture; call status and statistics, system status, ISDN status query
ISDN maintenance	Bit error rate (BER) test on ISDN links, local loopback, and B/D channel status query
Version upgrade	Upgrade via device Web interface, or batch upgrade via remote automatic management system
Matching tool	Finder software is used to find the device IP address within the local area network (LAN)

Key Specifications: 4 E1/T1 Interfaces, Concurrent Calls, and Power Supply Mode

As an IP access gateway, the interface and operating parameters of the IDM MAG-2E1 E1 digital trunk gateway are subject to the product documentation. The table below summarizes hardware interfaces, processing capacity, power supply, and environmental specifications for selection and equipment room conditions verification. The upper limit of concurrent calls is determined by the number and format of E1/T1 interfaces, and the power supply mode must be determined according to whether the site is an AC equipment room or a DC equipment room.

Item	Parameter/Specification	Description/Applicable Conditions
Network ports	RJ45, 4×10/100/1000 Base-T, adaptive	Used for connecting to softswitch, IMS platform, and NMS
T1/E1 interfaces	4 (120 concurrent calls at full configuration)	E1 format 30 B+D, upper limit of concurrent calls at full configuration is 120
SD card interface	1	For local file storage
CON configuration interface	RJ45	Local configuration and maintenance
System memory	512MB	—
Flash memory	64MB	—
Processing capacity	6000MIPS	Still performs voice processing, echo cancellation, and fax relay at 120 concurrent calls
Physical dimensions	H×W×D (1U): 44×440×300mm	Rack-mounted installation
Net weight	Within 3kg	—
Single/dual AC power supply	100 to 240 volts, 50/60 hertz, within 1 ampere	Single or dual power supply selectable for AC equipment rooms
Single/dual DC power supply	-36 to -72 volts, within 2.5 amperes	Covers -48V nominal DC, suitable for equipment rooms powered by DC distribution panels
Overall power consumption	18W	Overall power consumption at full configuration
Installation method	Rack-mounted	1U standard cabinet installation
Operating environment	Temperature 0 to 40℃; relative humidity 10% to 90% (non-condensing)	Equipment room and station building environments
Storage environment	Temperature -40 to 70℃; relative humidity 5% to 90% (non-condensing)	Transportation and storage conditions
Lightning protection	3.5kV	Outside line side protection

How Does ISDN PRI Trunk Access Interconnect with an Existing SPC Exchange?

The key to ISDN PRI trunk access lies in matching the trunk format, signaling type, and peer switch model. The PSTN access side of the Raytrans IDM MAG-2E1 E1 digital trunk gateway supports both E1 ISDN PRI (30 B+D, Chinese standard) and T1 ISDN PRI (23 B+D, ANSI NI-2 North American standard). The switch type is compatible with 5ESS series and DMS series, so it can adapt to the existing SPC exchanges of industry users. Before access, the trunk format, signaling type, and time slot occupation mode must be verified item by item with the peer end.

When an E1 digital trunk gateway interconnects with an SPC exchange, the physical layer operates according to ITU-T G.703/G.704 standards, with a single link rate of 2.048Mbps and HDB3 line encoding. The D-channel at the signaling layer follows ITU-T Q.921/Q.931 recommendations. Number and routing processing is completed on the device side, supporting number conversion, call routing (500 entries), and number bitmap. Call detail records (CDRs) can be sent to the billing system through the RADIUS billing interface. In upgrade projects, the number plan of the existing SPC exchange does not need to be readjusted.

In-band signaling and fax require separate confirmation of the encoding method. The DTMF of the IDM MAG-2E1 E1 digital trunk gateway supports three modes: in-band voice transmission, RFC2833 and SIP-INFO. When interfacing with an attendant console, IVR or secondary dialing services, select according to the capabilities supported by the opposite end. For fax, G.711 transparent transmission fax and T.38 fax are supported, compatible with G3 fax machines, and the transparent transmission rate can reach 33.6kbps. When link jitter is significant, switching to T.38 can reduce fax failures.

Why Does a Private Network Trunk Access Gateway Need Dual Power Supplies and DC Power Supply?

The availability of a private network trunk access gateway directly determines whether trunk telephone services can continue. The IDM MAG-2E1 E1 digital trunk gateway implements redundancy design at three levels: power supply, network and registration. On the power supply side, it supports single/dual AC power supply or single/dual DC power supply, and can be configured with 1+1 power supply modules. On the network side, it provides dual network port redundancy protection, so a local network failure does not affect calls. On the registration side, it provides a disaster recovery mechanism for active/standby SIP server switchover, so when the primary server fails, trunk services switch to the standby server. The three levels of redundancy jointly support continuous operation under unattended conditions in a private network equipment room.

DC power supply is an actual constraint of equipment rooms in industries such as electric power and rail transit. In an equipment room with centralized power supply from a DC distribution panel, a DC-powered trunk gateway can draw power directly from the -48V DC system, eliminating the AC inverter stage. The IDM MAG-2E1 E1 digital trunk gateway supports -36 to -72V DC input (within 2.5 amperes), and the input range covers the -48V nominal voltage. For AC equipment rooms, the 100 to 240V AC power supply version is selected. Both power supply versions support single power supply and dual power supply configurations.

Low power consumption and a wide storage temperature range reduce equipment room requirements. The IDM MAG-2E1 E1 digital trunk gateway has an overall power consumption of 18W, and its 1U rack installation does not take up additional cabinet space. The operating temperature is 0 to 40°C and the storage temperature is -40 to 70°C. The device provides 3.5kV lightning protection and can be deployed directly in a communications equipment room or a station building along the line.

Differentiated Value: 4-Channel E1/T1, 120 Concurrent Calls and Dual Power Supply Redundancy

The differentiated value of the IDM MAG-2E1 E1 digital trunk gateway is concentrated in three aspects: standalone trunk aggregation capability, redundancy and unattended adaptation, and dual-format trunk interfacing. The three values and their corresponding capabilities are shown in the table below. The parameters in the table are compiled from product documentation. For the specific configuration, please confirm with the optical multiplexer manufacturer based on project requirements.

Differentiated Selling Point	Corresponding Capability	Customer Value
4-channel E1/T1 interfaces, 120 concurrent calls at full configuration, 1U rack high-density access	Provides 4-channel E1/T1 interfaces; in E1 format, a single link is 30 B+D, and 1 to 4 links can be configured; the upper limit of concurrent calls at full configuration is 120; the unit has 6000MIPS processing capacity	A single 1U device completes trunk aggregation for a medium-sized private network, without the need to stack multiple devices or add external trunk boards
Dual network ports, dual power supply redundancy and active/standby SIP switchover	Dual network port redundancy protection, single/dual power supply configuration, 1+1 power supply modules, active/standby SIP server switchover	When a single point of failure occurs in power supply, network or softswitch server, trunk services are not interrupted, supporting continuous unattended operation of the private network
Dual format of E1 ISDN PRI (30 B+D) and T1 ISDN PRI (23 B+D)	The PSTN access side is compatible with Chinese standards and the ANSI NI-2 North American standard; the switch type is compatible with the 5ESS series and DMS series	Adapts to the existing SPC exchange of industry users, so trunk upgrades do not require replacing the opposite-end equipment

Typical Application Scenarios

The typical networking approach of the IDM MAG-2E1 E1 digital trunk gateway is to connect the E1/T1 links on the trunk side to the PSTN or an existing SPC exchange, and connect the network ports on the IP side to the local area network where the softswitch, IMS platform or command and dispatch system manufacturer platform resides, so that trunk telephone and IP voice services intercommunicate on the same network. The following three types of private network scenarios have concentrated requirements for the reliability, power supply mode and security protection of trunk access.

Electric Power and Energy Private Network: Trunk Aggregation in a DC Equipment Room

Power dispatch telephones and plant and substation administrative telephones are mostly carried by SPC exchanges, and the equipment room power supply is usually provided centrally by a -48V DC distribution panel. The IDM MAG-2E1 E1 digital trunk gateway uses -36 to -72V DC input to connect directly to the existing DC power system, and uses 4-channel E1/T1 interfaces to aggregate the PRI trunks of dispersed sites to the dispatch softswitch side. At full configuration, 120 concurrent calls can cover the trunk traffic of a regional private network, and the 1U rack installation facilitates capacity expansion in an existing communications cabinet. An unattended substation communications equipment room can deploy it on the spot, and trunk services continue to run with the station's DC system.

Rail Transit Private Network: Trunk Access for Station and Section Telephones

The official telephones and section telephones of rail transit and railways need to be connected from station switches to the line communication network. The IDM MAG-2E1 E1 digital trunk gateway interfaces with existing transmission and switching equipment according to the ITU-T G.703/G.704 standards, converts E1 PRI trunks into SIP signaling for access to the line softswitch, and uses dual network ports and dual power supply configuration to cope with station power supply and network fluctuations. The bit error rate (BER) test of the ISDN link and the local loopback query can locate trunk degradation without affecting calls.

Military and Government Private Network: Encrypted Trunks and Centralized Network Management

Military and government private networks have high requirements for the security and manageability of trunk access. The IDM MAG-2E1 E1 digital trunk gateway supports HTTPS, SSH, TLS and SRTP protocols as well as SIP signaling encryption and media stream encryption, and works with access whitelist, Ping prohibition and trusted addresses to prevent malicious intrusion. The device supports remote management through the network management system, automatically downloads configuration files via TFTP, FTP, HTTP or HTTPS, and can also obtain the ACS address via DHCP option 66 or redirection for bulk provisioning. Port voice capture and packet capture provide a basis for post-event tracing.

Summary

The IDM MAG-2E1 E1 digital trunk gateway concentrates 4-channel E1/T1 trunk access, 120 concurrent calls at full configuration, SIP/IMS interfacing and 512 SIP trunk account registrations in a 1U rack, and forms redundancy with dual network ports, dual power supply redundancy and active/standby SIP server switchover, while adapting to the DC equipment rooms of electric power and rail transit with -36 to -72V DC power supply. For electric power, rail transit and military and government private network users who are migrating trunk telephone services to an IP voice network while needing to retain existing E1/T1 trunks, the IDM MAG-2E1 can be incorporated into the overall communication plan as a trunk access and aggregation node. For the specific number of links, power supply version and signaling type, please confirm with the manufacturer based on on-site conditions.