Design
Product colour	Blue
Enclosure material	Plastic
LED indicators	LAN, Power, Status, WAN
Features
Voice codecs	CNG, G.168, G.711, G.723.1, G.726, G.727, G.729A, G.729B, VAD
Management features
Web-based management
Quality of Service (QoS) support
Reset button
Network
Ethernet LAN data rates	10,100,1000 Mbit/s
Networking standards	IEEE 802.1Q, IEEE 802.1p
Modulation	DTMF
Differentiated services (DiffServ) supported
Operational conditions
Operating temperature (T-T)	5 - 40 °C
Storage temperature (T-T)	-25 - 85 °C
Performance
Control display unit
Ports & interfaces
Ethernet LAN (RJ-45) ports	2
Foreign eXchange Station (FXS) ports quantity	4
WAN connection	Ethernet (RJ-45)
Power
Input voltage	110 - 220 V
Input frequency	50/60 Hz
Output voltage	12 V
Output current	1 A
Protocols
Supported network protocols	IPv4, TCP/UDP, ICMP, ARP, RTP, RTCP, PPPoE, PPTP, L2TP, DNS, Dynamic DNS, STUN, DHCP client/server, NAT, RIP, SPI Firewall, HTTP/HTTPS, FTP/TFTP, SNMP
VoIP protocols	SIP(RFC 3261)
Supported protocols	SIP
Security
Firewall security
VLAN support
Weight & dimensions
Width	167 mm
Depth	133 mm
Height	33 mm

The Audiocodes MP204B/4S/SIP is a VoIP telephone adapter designed as a gateway/controller for integrating analog telephone systems into IP-based networks. The device features four FXS ports for connecting analog telephones, modems, or fax machines, and supports the SIP protocol according to RFC 3261. It is suitable for use in small to medium-sized enterprises as well as home applications where a cost-efficient migration from analog to IP telephony systems is required. The device has a compact, blue-painted plastic housing and is designed for use in standard network infrastructures.

Applications

The Audiocodes MP204B/4S/SIP is suitable for connecting analog telephone systems to VoIP networks. The four FXS ports allow connection of up to four analog endpoints, enabling existing telephone systems to be integrated into an IP telephony system. The device is particularly suitable for companies wishing to perform a step-by-step migration from analog to IP-based communication systems without having to abandon existing endpoints. The integrated firewall and router functions ensure a secure network connection.

Functions and Equipment in Detail

The device features two Ethernet LAN ports (RJ-45) with data rates of 10, 100, and 1000 Mbit/s, enabling flexible network integration. A WAN port (RJ-45) is used for connecting to the public network or an internet service provider. The integrated control display unit enables visual monitoring of the operational status. LED indicators for LAN, power, status, and WAN signal the device's operational state. Support for VLAN (IEEE 802.1Q) and Differentiated Services (DiffServ) enables targeted network traffic management.

Technology Explained Simply

The Audiocodes MP204B/4S/SIP uses a variety of voice codecs, including G.711, G.723.1, G.726, G.727, G.729A, and G.729B, to optimize voice quality during transmission over IP networks. Support for VAD (Voice Activity Detection) reduces bandwidth usage by transmitting data only during voice activity. The DTMF modulation technique enables transmission of tones used during dialing or with fax machines. The integrated firewall provides protection against unauthorized access, while support for NAT and DHCP client/server simplifies network configuration.

Compatibility and Accessories

The device is compatible with SIP-based VoIP systems and supports a wide range of network protocols, including IPv4, TCP/UDP, ICMP, ARP, RTP, RTCP, PPPoE, PPTP, L2TP, DNS, Dynamic DNS, STUN, DHCP, NAT, RIP, HTTP/HTTPS, FTP/TFTP, and SNMP. Support for Quality of Service (QoS) ensures prioritized transmission of voice data to minimize delays and packet loss. Web-based management enables configuration and monitoring of the device via a standard web browser.

Mounting and Installation

Installation is carried out via the LAN and WAN connection options as well as the four FXS ports. Power supply is provided by a power adapter with an input voltage of 110–220 V and an output voltage of 12 V at a current of 1 A. The operating temperature range is 5 to 40 °C, and the storage temperature range is -25 to 85 °C. The device is designed for indoor use and requires no special mounting conditions.

Advantages in Operation

The combination of four FXS ports, SIP support, and integrated router and firewall functions enables simple and secure integration of analog telephone systems into IP networks. The web-based management and QoS support ensure user-friendly configuration and reliable voice transmission. Support for multiple voice codecs ensures flexibility in adapting to different network conditions.