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Converter TDM over IP for the fixed access networks

Technical Requirements Specification for Gateways TDMoIP or Converters E1/ETH

Product description and scenarios for its use

Converter TDMoIP is a device that uses technological solutions to organize communication channels for TDM equipment via Ethernet.

Converters TDM over IP for the fixed access networks - TDMoIP appearance

Pic 1. TDMoIP Gateway appearance

Converter shall provide TDMoIP in order to transsmit E1 signals over IP networks.

To meet the synchronization needs, TDMoIP, CESoPSN, SAToP standard protocols have been defined to handle pseudowire and circuit emulation over paquet switched networks.

Converters TDM over IP for the fixed access networks

Pic 2. Transmission of E1 signals through the TDMoIP converter

Converter TDMoIP is an access gateway that performs these functions for E1 streams with G.703, G.704 framing over an Ethernet based IP network while being compliant with the requirements listed below.

General technical requirements

The TDMoIP gateway (E1/TH converter) must meet the requirements for this type of device. The main technical requirements are presented below.

Usage profiles

To provide high-quality and uninterrupted communication services, the Device must work 24/24, 7/7, 365 days a year with a 99.9% availability level.

Functional characteristics

  • The product must provide the capability of mixing the DS0 timeslots between the E1.
  • The product must provide End-to-end synchronization with Clock recovery mechanism over packet-based networks.
  • The product must provide MASTER clock to E1 wires.
  • The product must provide Carrier class clock reliability.
  • The product must be compliant with IETF RFC : RFC 4553 (SAToP), RFC 5087 (TDMoIP), RFC 5086 (CESoPSN), RFC 4618.
  • The product must offer capabilities of 802.1p QOS tagging and prioritization.
  • Secure management protocol must be used for configuring the product (ssh instead of telnet ; https instead of http ; …).
  • The product must be compliant with Syslog protocol.
  • The product must be compliant with The SNMP V3 management protocol.
  • The product configuration must be able to be made with a local direct connection to the device.
  • The product configuration must allow the ability to setup several class of users according to privilege level (super user, read-only users).

Options or hardware configuration

Terratel TDMoIP gateway or E1/ETH Converter, depending on the customer’s technical specifications, can have from 1 to 16 ports in one housing with an RJ-45 connector for connecting E1 interfaces.

To transfer traffic to Ethernet, control and monitor the operation of the device, a port with an RJ-45 connector or an SFP slot can be used to integrate the device directly into the optical backbone.

Physical characteristics and interfaces


The product must fit the following dimensions:

  • width: 19 inches
  • height: 1U
  • length: 300mm

For devices with up to 8 E1 interfaces, the case dimensions can be optimized (the case width will be 9.5 inches).

For a device with 1 E1 interface, TERRATEL offers an original design in the SFP form factor.



The product must be compatible with a 220 VAC (50Hz) power supply or 48 VDC.

The product’s electrical consumption must not exceed 10 W.


Electronic interfaces

Physical interfaces for E1 must be: Balanced 120 Ω Cat. 5, RJ-45 to RJ-45.

An interface port must be dedicated for the management of the device.

General requirements concerning the product


The End of life should come no earlier than 10 years of operation.


Regulatory and legal requirements

The product must comply with the following regulations:

  • ROHS: Decree 2011/65/EU of 8th June 2011, “RoHS 2” [DA1],
  • REACH: Regulation 1907/2006/EC of 18th December 2006 [DA2]

The product must comply with CE marking regulations (mandatory to deliver products on European market).

Environmental requirements

The product must be able to operate under the following conditions:

  • Temperature: 15 to 35°C
  • Relative humidity: 10 to 80% humidity without condensation

Requirements for equipment maintenance services

Support services comprises of:

  • Help Desk service
  • Software Support Service&Software Upgrade
  • Knowledge Base Service
  • Regular Reporting all performed by the Supplier

The Supplier must provide support services or parts thereof in accordance with the terms and conditions agreed with the Purchaser.

The Customer may perform Support services or parts thereof on his own or order parts thereof from third parties.

Compliance with the requirements

The TDMoIP gateway (E1 / ETH converter) from TERRATEL fully meets the requirements for this type of equipment.

Device Specifications

The main technical characteristics of the E1 / ETH converter device are shown below.


Converter provides E1 connectivity over PWE with following encapsulation:


TDM Synchronization

E1/ETH converter supports the following functions for synchronizing TDM devices: recovered from the network, from the E1 interface and an internal source.


The internal bridge operates in VLAN-aware or VLAN-unaware mode. VLAN stacking separates management traffic between user traffic.

The traffic separated by assigning different VLAN IDs to different services.

Device support folloving protocols

• SAToP (rfc 4553);
• CESoPSN (rfc 5086);
• CESoETH (MEF-8).
• Adaptive sync recovery algorithm
• BER-test functionality

Device shall support following E1 loops

• Remote loopback
• Local loopback

Scenario P2P Point to Point

Scenario P2P Point to Point Network Diagram

Pic 3. Scenario P2P Point to Point

Scenario P2MP Point to Multi-Point (TDM Multiplex)

Scenario P2MP Point to Multi-Point Network Diagram

Pic 4. Scenario P2MP Point to Multi-Point


  • Number of Ports (1)
  • Connector RJ-45

E1 INTERFACE – ITU-T Rec. G.703, G.704

  • Number of Ports (1-8)
  • Data Rate 2.048 Mbps
  • Line Code HDB3
  • Framing Framed or Unframed E1 G.703/704 support
  • Line Impedance 120 Ohm bal, connector RJ-45

Power supple

AC/DC Power Supple: 100–240 VAC, 50/60 Hz or 48/60 VDC nominal (40–72 VDC).


TDMoiP unit can be managed using the following ports and applications:

  • Remote inband via separated VLAN ID
  • Local management (RS-232; web/CLI) or other


Password-protected Telnet and local terminal access.

Management traffic can be separated from user traffic by creating dedicated (VLAN) flows.

MNG traffic shall be terminated in device (noi propagation to ETH (LAN) port


Converter shall be compact device (no mudular) which can be easyly installed at the Customer side.

Device shall support following statistics:

  • Alarms E1, Ethernet, System and Maintenance
  • Circuit emulation statistic with per-bundle resetting possibility
  • ARP-table of peers
  • Sync statistic
  • G826 statistic for E1 interfaces with per-channel resetting possibility
  • Packet/error counters for Ethernet interfaces, reset is possible only for all counters
  • RSTP status
  • Pseudo-wire connections statistic

Device shall support following configuration MNG

  • Configuring of E1 interfaces (physical/channel layers)
  • Table of peers
  • Table of bundles
  • Configuring of Ethernet interfaces
  • VLAN table, QoS-CoS configuring
  • RSTP configuring (bridge settings + LAN-ports settings)

Configuration and SW management

  • The software fully supports configuration management – Apply / Confirm / Backup / Restore
  • The software provides commands to load / unload the configuration via TFTP
  • Supports TFTP software update function and update confirmation

Fault Maintenance and Maintenance tools

Hard reset the device.

Other features

Provides support for monitoring and control using the WEB interface.

Supports independent reset of E1, Ethernet and RSTP settings.

Alarm logging is maintained (internal, displayed by LOG commands, and support for external syslog server).


The device software supports TDMoE functionality, which allows E1 data to be transmitted over packet networks using Pseudo Wire Emulation (PWE).

Pseudo Wire Emulation (PWE) technology is called TDMoE (TDM over Ethernet).

This technology allows existing TDM solutions to be easily migrated to packet networks, using them as a low-cost transport medium.

The device supports the Batch emulation configuration scheme.

In particular, dynamically creating / removing packages for each E1 interface without affecting other active packages.

Specialized monitoring system as an option for equipment maintenance services.

The network monitoring system is responsible for timely response to an emergency situation in the operation of TDMoiP gateways installed on the Customer’s telecommunication network.

A specialized network monitoring system allows you to control and promptly inform about the occurrence of emergency events and key operating parameters of digital TDMoiP gateways.

The network monitoring system uses SNMP (Simple Network Management Protocol) to operate on an Ethernet network. This application is a product of Terratel and is the optimal tool for monitoring the health of the network as a whole.