Modernizing Legacy Telephony with E1 Voice Multiplexer Technology

In the context of digital transformation and the rapid development of fiber-optic communications, enterprise voice systems are facing unprecedented challenges. High stability, high clarity and multi-service integration capabilities have become the core demands of enterprise voice communications. As an important bridge connecting traditional telephone systems and fiber-optic networks, the performance of telephone over fiber multiplexers directly determines the quality of voice communications and the business continuity of the system.

This article will start from five major technical dimensions to comprehensively analyze the selection strategy and deployment points of telephone over fiber multiplexers, and especially introduce a product commonly used for point-to-point transmission 1-Channel Telephone over Fiber Multiplexer, to help enterprises build a safe, reliable and efficient voice network.

Voice quality assurance: the key guarantee for clear calls

Clear voice and real-time transmission are the basic functions of telephone over fiber multiplexers. Mainly focus on the following aspects:

● Low-latency transmission

Telephone over fiber multiplexers should support end-to-end delay ≤20ms to ensure smooth conversations. Especially in scenarios such as finance and emergency dispatch, low latency is crucial.

● Echo suppression and noise reduction processing

The equipment should support G.168 standard echo suppression and DSP digital signal processing technology to dynamically eliminate background noise and provide a clearer voice experience.

● Bit error rate control

Through forward error correction and digital equalization mechanisms, reduce bit errors and packet loss in long-distance transmission to ensure complete transmission of voice data.

Multi-service integration: carrying voice, data and video

Modern communications are no longer limited to single voice. Voice over Fiber equipment must support multiple services such as data and video.

● Rich interfaces

Mainstream telephone optical terminals are usually configured as follows:

FXS/FXO over fiber: connect to traditional telephone terminals;

E1 over fiber: connect to PBX switches;

Gigabit Ethernet ports: support network data transmission;

SFP optical ports: adapt to different fiber distances and wavelengths.

● Protocol compatibility

Support mainstream protocols such as SIP, H.248, TDM over IP, etc., to ensure compatibility with various IP-PBX and voice gateway systems.

● QoS mechanism

Through QoS strategies such as 802.1p and DiffServ, voice data is forwarded preferentially to ensure voice clarity, and stable operation can be achieved even in hybrid transmission networks.

Environmental adaptability: Industrial-grade guarantee for stable operation

Facing harsh environments such as outdoor cabinets, computer rooms, and rail transit, telephone optical transceivers must have the following capabilities:

● Wide temperature and voltage range

Supports -40℃~+75℃ ambient temperature, suitable for deployment in extremely cold or high temperature areas.

● Lightning and surge protection

Through 6kV surge protection, it complies with the IEC 61000-4-5 standard and effectively responds to lightning and surge risks.

● Vibration and corrosion resistance

The aluminum alloy shell with IP30~IP65 protection level is suitable for heavy-load environments such as railways, power, and mines.

Security protection: Ensure voice communication security

Today, when data security is becoming increasingly important, telephone optical transceivers need to build a solid security line from both physical and data levels.

● Physical security

Supports port locking, case encryption, anti-plugging alarm and other functions to prevent illegal access.

● Data encryption

Supports SRTP, AES-128/256 encryption protocols to prevent voice from being monitored or tampered with.

● VLAN isolation

Isolate voice from other data services through VLAN technology to reduce the risk of cross-network attacks and improve the overall security of the system.

Intelligent operation and maintenance: Reduce management and maintenance costs

Intelligent network management is an important support for large enterprises to deploy fiber-optic voice systems.

● Remote monitoring and management

Supports SNMP/Web/CLI management, and can remotely view device status (temperature, voltage, optical power, etc.) and perform configuration management.

● Fault self-healing mechanism

Through ring network redundancy (such as RSTP, ERPS protocol), when a link is interrupted, it will automatically switch to the backup link in less than 50ms.

● Energy-saving design

Complies with IEEE 802.3az standard, standby power consumption is as low as 5W, supports intelligent fan control, effectively extends equipment life and saves operating costs.

Typical deployment plan reference

● Corporate headquarters networking

Select E1/PRI/BRI interface telephone optical transceiver, connect to the operator's voice relay, and realize public network and intranet voice intercommunication.

● Branch office interconnection

Multi-channel FXS/FXO over fiber optical transceiver + SFP module to realize cross-building and cross-park voice intercommunication, support PoE power supply to simplify deployment.

● Emergency command communication

It is recommended to use high-availability voice optical transceiver with dual power redundancy + 4G wireless backup + GPS clock synchronization to deal with emergencies such as network disconnection and power outage.

Recommended selection of telephone optical terminal (brief table)

Item Recommended parameter configuration

Number of channels 1/4/8/16/32/64 FXS or FXO

Interface type FXS, FXO, E1, Ethernet, SFP, RJ45

Protocol support SIP, TDM, H.248, MGCP

Management method SNMP v2/v3, Web UI, CLI

Environmental adaptability -40℃~+75℃, IP65 housing, anti-vibration and anti-electromagnetic interference

Security capability SRTP encryption, VLAN isolation, 802.1X authentication

Product deployment type Point-to-point, one-to-many, industrial ring network, emergency communication

Conclusion: Core equipment for building a converged voice communication network

1-Channel Telephone over Fiber Multiplexer is gradually evolving from a single voice transmission tool to a core communication device that integrates voice, data, video, security, and intelligent management. With the development of 5G, the Internet of Things, and industrial digitalization, Voice over Fiber solutions will play a more extensive role in energy, rail transit, government affairs, finance, and telecom operators.

When deploying a voice system, enterprises should flexibly select telephone optical transceiver products of different specifications based on actual scenarios and business needs to ensure the stable operation and future scalability of the system.