FAQ’s & Guides

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Our FAQ’s and guides are designed to shed light on some of the more complex technical subjects related to boh our products and wider telecommunications systems.

What is OTT and how is it impacting Telecom Service Providers?

January 28, 2019
Over The Top (OTT), also sometimes known as Telco-OTT, is a term used to describe when a provider delivers audio, video and other media over an IP network (such as the internet), bypassing the traditional operators network completely. OTT providers...
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The 7 Layers of the OSI Model

January 21, 2019
When describing telecommunication networks, often we refer to layers (such as Layer 1, Layer 2 and so on). This article describes, in detail, what exactly these layers are, how they are defined and where precisely the terminology comes from. The...
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Packet Switching Explained

January 10, 2019
What is packet switching? Packet switching is a networking communication method used in telecommunications systems, whereby data is grouped into blocks called packets and routed through a network using a destination address contained within each packet. By breaking the communication...
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SD-WAN (Software Defined Wide Area Networks) Explained

January 2, 2019
As with most emerging and evolving trends in the telecommunications industry, the definition of SD-WAN is varied among vendors and carriers as each are looking to promote the version which best suits their capabilities. Varying definitions have created some confusion...
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Synchronous Transport Module (STM) in Telecommunications

November 21, 2018
In telecommunications networks, STM or Synchronous Transport Module is a fiber optic network standard for SDH (Synchronous Digital Hierachy). The transmission format is considered the main building block for Synchronous Digital Hierarchies. In order to understand exactly what STM is...
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SFP Compatibility Guide

November 13, 2018
As fiber optic technology continues to develop and is deployed within telecommunication networks, optical transceiver modules including manufacturer compatible SFP’s have been adopted within data center’s around the world. This article is designed to help to understand the compatibility and...
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Telecommunication Network Demarcation Point: Explained

October 30, 2018
In telecommunications networks, the demarcation point (often abbreviated to DEMARC and otherwise known as boundary point or network boundary point) is the physical point at which the public switched telephone network ends and the private network of the customer begins....
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Future proofing your legacy telecommunication systems

October 23, 2018
Moving away from established legacy telecommunication systems is not always feasible. It may just be a timing issue, that replacement of entire systems is too cost prohibitive or that the existing systems are so deeply integrated in your business or...
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FTTX – Fiber to the X: Explained

September 25, 2018
FTTx stands for Fiber to the X (where X represents a particular name or object, such as ‘home’ or ‘cabinet’). It is a telecommunications network architecture that is used within the local loop (the last section of the providers network...
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Session Initiation Protocol (SIP)

September 17, 2018
Session Initiation Protocol (SIP) is used at the application-layer in telecommunication networks to control, establish, modify and end multimedia sessions. Sessions are exchanges of data between a group of participants. With SIP, participants and media can be added and removed...
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What is OTN (Optical Transport Network) in telecommunications?

September 12, 2018
Optical Transport Networking is a telecommunication industry-standard protocol which provides a way of multiplexing different services onto optical light paths. It was originally designed to promote network evolution beyond SONET/SDH. As network service providers tackle the ever-increasing issue of rapid...
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Multi-Protocol Label Switching (MPLS): Explained

September 4, 2018
MPLS is a traffic routing mechanism that is used in telecommunications networks to shape traffic flows when data is sent between network nodes. Using this protocol, packets are forwarded on the switching level (rather than the routing level). MPLS can...
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Coarse and Dense Wavelength Division Multiplexing: Explained

August 15, 2018
Wavelength Division Multiplexing (WDM) uses fiber optic cables to transmit a large number of data streams. This is favoured over the conventional use of Frequency Division Multiplexing (FDM) and Time Division Multiplexing (TDM) systems. There are two main types of...
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What is the difference between analogue and digital transmission?

July 31, 2018
When we talk about analogue or digital, we are referring to the type of transmission of a signal. There are a number of key differences between analogue and digital signal transmission. Analog Transmission An analogue signal (otherwise known as a...
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How telecommunications network providers can overcome today’s customer challenges and reduce downtime

July 26, 2018
As the telecommunications industry continues to evolve and react to an ever more digitised society, customer expectations are continually rising, particularly when it comes to more consistent and faster connectivity with as limited downtime as possible. This increasing pressure from...
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Switching Systems in Telecommunication Networks

July 5, 2018
What is switching? Switching is the method that is used to establish connections between nodes within a network. Once a connection has been made, information can be sent. Telephone switching usually refers to the switching of voice channels. There are...
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Using multiplexers to optimise fiber

July 4, 2018
WDM (Wave Division Multiplexing) is used to optimise and maximise the use of fiber in telecommunications. This is achieved by multiplexing and demultiplexing multiple data streams so that they are able to be transported simultaneously over a single fiber. By...
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EPON vs GPON – Introduction and comparison

June 11, 2018
As capacity demands continue to increase for network providers, the versatility of access networks must also expand in order to meet this growing demand. Optical network access technologies have become a key focus for operators looking to build for the...
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Power over Ethernet: Explained

June 8, 2018
Power over Ethernet (PoE) has revolutionised the way that wireless LAN Access Points, IP telephones and other IP based network devices receive power, by enabling the transfer of DC power at the same time as data via standard network cabling...
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What is Frame Relay in telecommunications?

May 30, 2018
Frame Relay is a wide area network technology which is used to specify the physical and data link layers of digital telecommunications channels using packet switching. Frame Relay was originally designed for transport across ISDN (Integrated Services Digital Network) infrastructure...
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What is DDM and DOM for Optical Transceivers?

May 15, 2018
What is DDM (Digital Diagnostic Monitoring)? DDM or Digital Diagnostic Monitoring is a technology which allows operators to monitor several parameters of the fiber optic transceiver, such as optical input/output levels, temperature, laser bias current and supply voltage. All of...
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Singlemode vs multimode fiber

May 10, 2018
There are two types of cables that are commonly used with fiber: Single mode and Multimode. Singlemode Fiber Singlemode cables are designed to carry light directly down the fiber. It is a single strand of glass fiber that has been...
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What is VoIP and how does it work?

April 20, 2018
VoIP or Voice over Internet Protocol, also known as IP Telephony or Internet Calling is an alternative way of making phone calls that can be less costly than standard telephone calls over PSTN (Public Switched Telephone Network). This article explains...
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Third-party vs branded optical transceivers – Does it really matter?

April 12, 2018
Over the last decade optical transceivers have become a key part of a network architects arsenal of equipment and are used frequently to assist in the evolution of modern networks. As technologies have improved and variants have been designed to...
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CDMA vs GSM: What’s the Difference?

March 27, 2018
CDMA and GSM are two acronyms that you will see regularly when reading about anything related to mobile telephony. This article explains what each of the two terms mean, how they are related, why they are different and why you...
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What is a virtual network operator (VNO)?

March 27, 2018
A virtual network operator or mobile virtual network operator (also known as a VNO or MVNO) are management service providers and network service resellers of other telecommunication service providers. VNO’s do not own or operate a telecommunications network infrastructure or...
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An introduction to optical transceivers in telecommunications

February 26, 2018
Optical transceivers are small, powerful devices that can transmit and receive data. In fiber optics, data is sent via an optical fiber in the form of pulses of light. This data travels at very high speeds and across extremely long...
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What is wireless spectrum and why is it so important in telecommunications?

February 19, 2018
What is spectrum? In wireless communications, signals travel from their source to a receiver via radio frequency. Everything from television, radio, GPS and mobile phone services transmit information in bits through the air in this way. The collection of radio...
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What is the difference between GBIC modules and SFP modules?

February 7, 2018
GBIC and SFP modules are both transceivers which are hot-pluggable, meaning they can be loaded into and out of a working telecommunication switch without the need for powering down. They are used to convert optical and electrical signals. GBIC stands...
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Why you shouldn’t worry about manufacturer EoL announcements

January 24, 2018
It is still possible to receive high quality support for your legacy telecommunications equipment long after a manufacturer EoL announcement Carritech offer alternative support solutions for legacy telecommunications equipment, allowing our customers the choice and flexibility to maintain, refresh and...
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What are SFP’s and why are they used in telecommunication systems?

January 16, 2018
SFP’s are small optical module transceivers which are hot pluggable (meaning they can be plugged in and out of a system without the need for shutting it down) and are used in telecommunication and data communication applications. They offer a...
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What is Modulation in Telecommunications?

January 9, 2018
What is modulation? Modulation is the process of encoding information from a message source in a way that is suitable for transmission. This is achieved by altering the characteristics of a wave. By superimposing a message on to a high...
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The Difference between Twisted Pair, Coaxial and Fiber Optic Cables

December 11, 2017
Twisted Pair, Coaxial and Fiber Optic cables are the three most common types of communication cables currently used in modern networks. The types of cables used to connect your network will affect key elements of your connectivity including the speed...
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What is LAA (Licensed Assisted Access) and why is it useful?

November 27, 2017
LAA (Licensed Assisted Access) was introduced in 3GPP release 13 as part of LTE Advanced Pro and is a method used to designate public spectrum in the speedy and currently spacious 5GHz band and has been designed to assist standard...
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Attenuation in telecom networks

November 8, 2017
Attenuation is a general term that refers to any reduction in the strength of a signal. It occurs with any type of signal, whether digital or analog and is a natural consequence of signal transmission over long distances. Put simply,...
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What is network densification?

October 30, 2017
As wireless subscribers continue to use more network resources than ever before, and data consumption continues to intensify; operators are racing to add more capacity in order to handle traffic and provide the speeds that customers have come to expect....
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What is dark fibre?

October 23, 2017
When operators lay downs fibre optic cabling for their networks, often they will overestimate the amount of infrastructure and cabling that is required, in order to ‘future-proof’ their network, allowing for data growth in the future. This unused infrastructure (which...
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What is G.fast and when will it be available?

September 26, 2017
G.fast is a telecommunications protocol standard for DSL (Digital Subscriber Line) local loops that are shorter than 500 meters (the local loop being the ‘final’ part of the infrastructure, also known as the last mile; it is the physical link...
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CSFB (Circuit-Switched Fall-Back): Explained

September 4, 2017
Circuit Switched FallBack (CSFB) is a technology whereby voice and SMS services are delivered to LTE devices through the use of GSM (global system for mobile communications) or another circuit-switched network. LTE is an all-IP technology and therefore cannot transport...
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VoLTE: What is it and how does it work?

September 4, 2017
VoLTE (voice over LTE) refers to voice calls that are made over a 4G LTE network instead of more traditional calls which are made by using CSFB (Circuit-Switched Fall-back), a system that switches back to 2G or 3G technologies just...
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When will 2G and 3G services be phased out completely?

August 30, 2017
As data traffic continues to grow every day, so too does the need to increase capacity within telecommunication networks. In order to do this MNO’s (Mobile Network Operators) need to look to acquire new spectrum or alternatively, make available more...
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Understanding Multiplexing in Telecommunications

August 16, 2017
All forms of telecommunications, including radio, telephone and television use multiplexing to send and receive information. Frequency division multiplexing (FDM), time division multiplexing (TDM), and wavelength division multiplexing (WDM) are all an extremely important asset to telecommunication processes and have...
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Fiber Optics: Explained (INFOGRAPHIC)

August 14, 2017
Fiber optic communication is a method used in telecommunications, to transmit information from one place to another via pulses of light which travel within an optical fiber. The light forms an electromagnetic carrier wave that is modulated to carry information,...
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Synchronous Digital Hierarchy (SDH): Explained

August 11, 2017
Following on from our article explaining PDH (Plesiochronous Digital Hierarchy), we describe the differences between PDH and SDH (Synchronous Digital Hierarchy). Around 1990, SDH was developed and launched to replace PDH systems and eliminate synchronization issues for bulk telephone and...
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The Plesiochronous Digital Hierarchy (PDH): Explained

August 10, 2017
Plesiochronous Digital Hierarchy (PDH) was designed to transport the huge amounts of data over digital equipment like microwave radio or fiber optic systems. Analogue transmission lines which used trunk lines between exchanges to carry multiple voice channels simultaneously (using frequency...
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What are the different types of PON (Passive Optical Networks) and what are they used for?

August 3, 2017
This article explores the various types of PON (Passive Optical Networks), how they differ and what they are used for. APON (ATM Passive Optical Networks) This was the very first of the PON standards and was based on ATM (Asynchronous...
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What is SDN (Software Defined Networking)?

July 17, 2017
SDN or ‘Software-defined networking’ is a type of network virtualisation that optimises network resources by allowing for easy adaptability of the requirements of users, applications and traffic. By separating the control plane and data plane within the network and creating...
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PSTN (Public Switched Telephone Network) Explained

July 10, 2017
What is the PSTN? The PSTN or Public Switched Telephone Network is the complete formation of the world’s circuit-switched telephone networks which are operated by national, regional, or local telephone operators and provide the infrastructure and services for public telecommunication....
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Access Network Layer: Explained

June 9, 2017
The access layer in telecommunications networks connects users to their immediate service providers. It is where the process of communicating within a network begins, by allowing users to interact with the communications system to enable initiation of user information transfer....
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What’s the attraction to GPON?

June 5, 2017
There are a number of reasons why operators have favoured the use of GPON (Gigabit Passive Optical Network) technology within their networks and none more so than its fundamental architecture. Unlike traditional networks which provide direct point-to-point links from customers...
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Core Network Layer: Explained

June 5, 2017
In telecommunications, the core network is the central element of a network that provides services to customers who are connected by the access network. There are a number of services that the core network provides, but one of the main...
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What is GPON (Gigabit Passive Optical Networks)?

May 25, 2017
GPON or ‘Gigabit Passive Optical Networks’ is a point-to-multipoint access mechanism. The main characteristic of GPON is the use of passive splitters which enable a single feeding fibre from the network provider’s central location to serve multiple users within their...
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A helpful guide to de-installing your telecommunication equipment

May 11, 2017
The decision to de-install your telecoms equipment can be one of the most resource demanding activities affecting your business. As part of this, careful consideration must be made with regards to planning, inventorying and carrying out the project. This will...
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Telecoms Handling, Shipping & Packaging

May 10, 2017
How is our telecoms equipment handled and shipped to ensure safe travel? There are a number of important procedures that should be followed by all who handle telecommunications equipment and package it for distribution around the world to ensure that...
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Why would carriers choose to buy used or refurbished telecoms equipment?

May 10, 2017
Many carriers worldwide continue to purchase used and refurbished telecoms equipment for their existing networks, choosing to opt for legacy equipment over newer technologies. In a world where we are constantly reminded that ‘newer is better’ we ask the question,...
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Don’t let your surplus telecoms equipment go to waste

May 2, 2017
Start generating revenue from your unwanted telecoms equipment If you have mobile or fixed line telecoms equipment that is surplus to requirements, obsolete or unused, do not throw it away or scrap it unnecessarily. This type of telecoms equipment isn’t...
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Telecoms Repairs Process: Explained

May 2, 2017
We ensure a methodical, systematic approach to guarantee high quality repair services. Receiving Equipment We match your purchase order to the equipment that we have received to ensure total accuracy. All discrepancies are forwarded to customer service for resolution with...
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What is Massive MIMO?

April 4, 2017
In February, we wrote an article explaining exactly what MIMO is. Now, we will be looking at the difference between MIMO and Massive MIMO. MIMO Recap Multiple-input-multiple-output (MIMO) is used in many wireless technologies to achieve more capacity without using...
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Why does the Alcatel 1600 range remain so popular?

March 28, 2017
We’re delighted to continue to help our customers locate spare and replacement parts as well as repair their Alcatel 1600 telecommunications equipment and we’ve noticed it has shown little sign of decline even so long after it was first released....
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What is Network Function Virtualisation (NFV)?

March 21, 2017
NFV or Network Function Virtualisation is the concept of replacing the dedicated network appliances (such as routers and firewalls within a business’s own premises) with separate software which takes on these roles but within commercial servers that are run and...
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Are existing mobile operator networks ready for the demands of AR and VR apps?

March 15, 2017
As apps and games have begun to increasingly rely on streaming and GPS tracking for VR (virtual reality) and AR (augmented reality) based apps and services, networks will experience more strain than they would ordinarily from ‘normal’ web-browsing. Although immersive...
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LTE, LTE-A & LTE-A Pro: Explained

March 9, 2017
LTE or Long Term Evolution is a series of 4G network standards that were agreed in 2008. The architecture used in LTE was designed to surpass the mobile data rates that were available using 3G technologies. In 3G networks, the...
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What are different types of small cells used for?

March 7, 2017
‘Small cells’ is the term used for operator-controlled, low-powered radio access nodes, including equipment that operators both within licensed spectrum and unlicensed carrier-grade WiFi. Whereas a base station has a standard range of up to 35 kilometres (around 22 miles),...
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What is MIMO?

February 27, 2017
MIMO  or 'multiple-input, multiple-output' is a wireless technology that, when deployed, uses multiple antennas at both the source (transmitter) and the destination (receiver). This allows for more data to be sent and received at the same time, unlike in conventional...
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Common Wi-Fi Connection Solutions

February 22, 2017
Are you experiencing a slow Wi-Fi connection? If your internet connection is running slowly it can be extremely frustrating. Even more so when if you are trying to complete work to a deadline. Below, we have put together a list...
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LAN vs WAN: What are the differences?

February 20, 2017
This article explains the differences, including advantages and disadvantages of LAN and WAN networks. LAN = Local Area Network Local Area Network connections are intended for local areas such as a house or office building and are designed to connect...
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An Introduction to Network Slicing

February 16, 2017
There have been a number of recent developments in 5G, including an announcement from South Korean company ‘SK Telecom’ that they are set to team up with Ericsson to collaborate on development of a core network for 5G that deploys...
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What is Small Cell Technology?

February 1, 2017
What are Small Cells? Mobile connectivity requirements are increasing at an unparalleled rate. Now that so many devices rely on wireless networks, particularly in highly populated areas such as towns and cities, network operators are forced to find robust solutions...
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Are you making best use of your surplus telecommunication assets?

December 9, 2016
Are your telecoms assets becoming a mess? Are you confused by the equipment you have and whether it is still valuable to your company? Are you trying to save room or make space? At Carritech, our staff have over 40...
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Tips for Managing Your Telecommunications Budget

December 6, 2016
This article has been designed to assist those who are making budget decisions on telecommunications equipment in order to maintain their existing networks. By offering some advice on how to keep costs under control while maintaining the best possible quality...
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Why choose a revenue share option over a quick sale?

November 23, 2016
This article explains the reasons why you should opt for a revenue share scheme such as Carritech’s ‘We Manage’ option, when looking to generate funds from your surplus telecommunications equipment. Let the professionals do the hard work - Selling telecommunications...
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Why choose Carritech as your telecoms support provider?

November 21, 2016
At Carritech, we provide support, repair and replacement services to our clients on a daily basis, to ensure their networks are fully operational. Whether your needs are large or small, we can help to provide the services that you require....
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Important questions to ask your telecommunications supplier

November 15, 2016
Telecommunications equipment can be hard to come by, especially legacy parts that are no longer manufactured. Therefore, when selecting the company which supports your businesses telecommunications networks, it is vital that you consider such things as the availability of stock,...
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6 Benefits of Buying from Carritech

August 22, 2016
6 Key Benefits of buying telecommunications products from Carritech The benefits to your business when buying refurbished access, transport, data networking or core switching equipment for your telecommunications network are substantial; not only do you get a product that is...
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How To Sell Used Telecommunications Equipment

August 3, 2016
How to sell used telecommunications equipment. Advice from a trade buyer. Having been a telecommunications equipment supplier since 2010 and with over 40 years’ combined experience in the industry, we are familiar with what helps clients sell used telecommunications equipment. In this...
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What are the benefits of purchasing from the telecommunications secondary market?

July 27, 2016
Without an extremely large budget and a long period of time to replace an entire system; operators need to make use of the secondary market to ensure that their legacy telecommunications infrastructure remains operational. This article explains why the telecommunications...
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We Purchase: Frequently Asked Questions

July 5, 2016
We Purchase FAQs: We have provided a list of our We Purchase FAQs to help you to find the answers you need easily. If we haven’t covered your question in this page, please contact us directly and we will be...
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