Frequently Asked Questions about digital VoIP gateways from Terratel

FAQ design features and functionality

Considering that Terratel is a developer, manufacturer and seller of VoIP gateways for the integration of digital interfaces E1/T1 and IP networks, we are asked quite diverse questions. These questions cover design features and functionality.

Below we will try to present the most frequently asked questions (FAQ) about VoIP gateways that we have received recently.

What is a digital VoIP gateway?

A VoIP gateway is hardware and software that converts TDM traffic from the PSTN (Publicly Switched Telephone Network) to IP packets, or vice versa for transport over Ethernet networks.
At the same time, the device is connected to the TDM side via the E1 interface, which is a digital data transmission standard with a bandwidth of up to 2048 kbps.

Is it possible to connect analog trunks?

Not. Our device belongs to the digital type of gateway to which E1 interfaces are connected.

What is an analog VoIP gateway?

It is a VoIP gateway that allows station devices such as analog telephones, analog POTS trunk lines to be connected through the FXS or FXO ports.

What is E1 port and what is the maximum number of E1?

E1 (interface, port, stream) is a digital data transmission standard corresponding to the primary level of the European PDH standard.
The capacity of the E1 stream reaches 2048 kbps.
The digital VoIP gateway has the following design options:

  • 2E1– 120 SIP
  • 4E1– 120 SIP
  • 8E1– 240 SIP
  • 16E1– 480 SIP

Is it possible to send a Fax through a Gateway?

Yes, it is possible.
VoIP gateways from Terratel fully support the T.38 fax codec.

What voice compression do Digital VoIP gateway support?

Digital VoIP Gateway supports standard codecs such as G.711, G.723.1, G.726 and G.729A/B.

What kind of signaling does the VoIP gateway support as standard?

The device can simultaneously support the following signaling and protocols: SIP, SS7 (supporting subsystem MTP2, MTP3, ISUP), ISDN PRI (DSS1, QSIG, Q.931), V5.2 LE, V5.2 AN, R2 MFC, R1.5.

How many SS7 links are supported?

A digital VoIP gateway in a 4E1 configuration supports up to 4 SS7 links, in a 16E1 configuration up to 16 SS7 links. That is, it is possible to configure one SS7 link for one E1 port.

Do VoIP gateways from Terratel support power redundancy?

Depending on the customer’s requirements for redundancy, the devices are equipped with power supplies in the following versions:

  • AC 220V
  • DC 48V
  • AC 220V + DC 48V
  • AC 220V + AC 220V
  • DC 48V + DC 48V

Does VoIP Gateway support LED indication and hardware reboot capability?

The device supports LED indication of various states of E1 ports and EHT ports.
On the front panel there is a button for hardware reset of the gateway to factory settings.

Can the VoIP gateway fallback to the PSTN connection if the Internet goes down or there is a power outage?

If an E1 backup channel switching unit (E1 Bypass) is supplied together with the VoIP gateway, this is possible.
E1 Bypass complete with VoIP gateway is designed to back up communication lines in case of power failure at the facility.
The E1 redundant channel switching unit acts as an emergency telephony switch and is a 19-inch patch panel with 48 RJ-45 ports of 1U standard size.

What are the warranty obligations?

Depending on the terms of delivery, Terratel provides a guarantee for the digital VoIP gateway for a period of 1 to 3 years.

What are the basic network diagrams for using a digital VoIP gateway?

In fact, there are many typical applications for using a gateway. The most common use cases include:

  • Connecting your VoIP telephone system to the public switched telephone network
  • Connecting traditional telephones to your VoIP phone system
  • SIP connection for traditional PBX system with E1 interface

You can get acquainted with other possible options and schemes of use on our website in the section “Solution for modernization of fixed and mobile networks”.

If you need a solution that is not described or it will be non-standard, please contact the specialists of Terratel.