Nexus Open Systems Ltd

Nexus Gamma Horizon & Collaborate

Gamma Horizon and Collaborate from Nexus is an enterprise-ready Unified Communications platform. The hosted UC Service provides features such as voice and video conferencing, instant messaging, presence, desktop and file sharing. A web platform and application allow real-time access to enable changes to features, configurations and users.


  • Audio, video and web conferencing
  • Instant messaging, presence and screen sharing
  • Works on any device; desktop, Mobile or handset
  • Microsoft Outlook integration
  • Online portal accessible from anywhere offering visibility and control
  • Seamless continuity between desktop and mobile applications
  • Intuitive and easy to use with real time changes
  • IP handsets can be configured remotely
  • Includes protection to safe guard against fraud
  • Lowers call costs across your organisation


  • Promotes the Public Sector
  • An end to end solution that can be tailored
  • Reliable and resilient voice and video platform
  • On demand solution with no hidden costs
  • Delivers business continuity and disaster recovery for your business
  • Platform is continuously evolving as it is cloud based
  • Quickly and easy begin online meetings with colleagues and customers
  • Reduces expenses as meetings become virtual
  • Provides remote working for staff delivering flexibility
  • Improves collaboration, agility, security, image and efficiency


£6.19 a user a month

  • Education pricing available

Service documents

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G-Cloud 12

Service ID

3 8 0 7 3 4 2 0 6 2 5 6 0 7 3


Nexus Open Systems Ltd Stuart Wilson
Telephone: 01392 205095

Service scope

Software add-on or extension
Cloud deployment model
  • Public cloud
  • Private cloud
  • Hybrid cloud
Service constraints
As a VoIP service, calls to 999 may not be possible, during a service outage where the customer loses total connectivity for example, owing to a power outage or the failure of all data access.
Horizon does not support the following:
Analogue phones and devices, although we do supply ATAs
ISDN data calls
Door entry options
Presentation of multiple CLIs per site or per user
IP handsets that have not been supplied by us
The call recording service on Horizon is not currently PCI or FSA compliant.
We do not support some fax and franking machinesused with an ATA
System requirements
  • A Horizon compatible data network (Confirm with Nexus)
  • Data access which is sized appropriately

User support

Email or online ticketing support
Email or online ticketing
Support response times
Standard SLA is for 2 hours response for Critical issues; 4 hours response for Major issues and 8 hours response for Minor issues.
User can manage status and priority of support tickets
Online ticketing support accessibility
None or don’t know
Phone support
Phone support availability
9 to 5 (UK time), Monday to Friday
Web chat support
Web chat
Web chat support availability
9 to 5 (UK time), Monday to Friday
Web chat support accessibility standard
None or don’t know
How the web chat support is accessible
Users can interact with our Technical, Sales and Training teams. Raising questions which are dealt with there and then. Alternatively we will take enquiries away and respond direct to users through email.
Web chat accessibility testing
None as yet
Onsite support
Yes, at extra cost
Support levels
Gamma provides one level of support for all Horizon customers 24x7x365 - included free of charge as part of the service charge. The following service levels apply with target resolution times:

Critical Fault - Loss of service. Multiple services affected - 4 Clock Hours
High - Loss of service - single service - 8 Clock Hours
Medium - Disrupted service - 3 Working Days
Low - Single number destinations or Quality of Service - 7 working days

Service availability for Horizon is:
Horizon Graphical User Interface (GUI) is 99.9%
Horizon user subscriptions is 99.5%
Horizon Auto Attendant, Call Recording, and Unified Messaging subscriptions - 99%
Mean Average PESQ Score target of 4.1 for G711 and 3.7 for G729.
Support available to third parties

Onboarding and offboarding

Getting started
We follow a defined process for on-boarding new clients to ensure that they have the assurance of our help, whilst at the same time remain in control of the cloud services which are often at the core of their business. Through the on-boarding process Nexus will complete a detailed assessment of: • Client’s strategic vision • Organisational culture • Current and future objectives • Desire business outcomes • Potential improvements to existing business processes • Project and programme delivery resources • Current governance and programmes. We can provide onsite training to our clients as well as instruction at our own training centre. User documentation is provided by way of client portal guide
Service documentation
Documentation formats
  • HTML
  • PDF
  • Other
Other documentation formats
  • .mpg
  • .doc
End-of-contract data extraction
Our Customer Portal is a secure online space giving customers complete visibility of the assets that we manage for them. We offer a complete view of their estate, including telephone numbers (CLIs), the product related to that number and its geographical location. All invoices are in one place and kept for 12 months for historical billing information on the services you have taken.
This information can be easily downloaded for extraction into excel.
End-of-contract process
At the end of the contract the customer moves onto a rolling 30 day contract on our standard rates. Through our online billing and reporting portal, customer can get their asset list, including numbers that can be ported away and details of the services they currently take with us. This will be provided at no additional cost. It is up to the new provider to port the numbers away.

Using the service

Web browser interface
Supported browsers
  • Internet Explorer 9
  • Internet Explorer 10
  • Internet Explorer 11
  • Microsoft Edge
  • Firefox
  • Chrome
  • Safari 9+
Application to install
Compatible operating systems
  • Android
  • IOS
  • MacOS
  • Windows
  • Windows Phone
Designed for use on mobile devices
Differences between the mobile and desktop service
We have a bolt on App (additional cost) that can be added as an option to Horizon. Upon successful download from the relevant app store onto the desktop, the user is able to log in to access a subset of Horizon functionality.
The mobile soft client app allows a user to make and receive calls on a mobile device, as well as accessing key settings for their service. It provides all the same functionality as the desktop soft client, with the exception of Click to Call.
Service interface
Description of service interface
Horizon provides a secure web portal - a simple, easy to use management system that allows the following tasks to be undertaken:
• Site Management–control site numbers & Schedules, Music on Hold, & Call Barring
• User Management–create/edit users & assign devices, telephone numbers, set call barring & optional services
• Group Management–manage IVR, ACDs & Hunt Groups
• Call Recording Management–call recording & manage storage
• Security–manage username & passwords including softclients
Statistical information across the estate for inbound & outbound calls can also be accessed.
Individual users also have access to a portal to manage their settings.
Accessibility standards
None or don’t know
Description of accessibility
Standard web-browser/app access with standard accessibility options associated with those web-browsers/apps.
Accessibility testing
Customisation available
Description of customisation
There is an extensive list of customisable features and functions on Horizon (available on request).
The service offers a range of clever features and an emphasis on control and administration through the web. For administrators, you can quickly configure the system according to your organisation’s changing requirements, whilst individual users can manage their calls easily and effectively.
Users can implement a wide range of features via the web portal, either at a company, site, or User level giving full and easy control of
an entire telephony environment, even over multiple sites.


Independence of resources
We undertake a monthly Capacity Planning Forum whereby the utilisation of every network component is reviewed against planning rules and sales forecast to ensure that we have sufficient capacity and overhead to manage our customer's requirements. Additionally there is weekly planning review on capacity management adjustments.
Each Horizon customer's resource requirements are taken into account and sufficient network is allocated to them. We also manage our network to spread traffic during very busy periods.


Service usage metrics
Metrics types
The Horizon service provides a range of on line call reporting on a per number basis. Full summary reports are provided; how many calls are getting through, where are my customers located, what are my call trends, when are my busy times. Detailed call analysis is available via the advanced statistics package.
Reporting types
  • Real-time dashboards
  • Regular reports
  • Reports on request


Supplier type
Reseller providing extra support
Organisation whose services are being resold

Staff security

Staff security clearance
Conforms to BS7858:2012
Government security clearance
Up to Security Clearance (SC)

Asset protection

Knowledge of data storage and processing locations
Data storage and processing locations
United Kingdom
User control over data storage and processing locations
Datacentre security standards
Complies with a recognised standard (for example CSA CCM version 3.0)
Penetration testing frequency
At least once a year
Penetration testing approach
‘IT Health Check’ performed by a CHECK service provider
Protecting data at rest
Encryption of all physical media
Data sanitisation process
Data sanitisation type
Deleted data can’t be directly accessed
Equipment disposal approach
A third-party destruction service

Data importing and exporting

Data export approach
Our Web Portal allows users access to their associated number ranges. Typically users will extract their applicable data in Excel or CVS format.
Data export formats
  • CSV
  • Other
Other data export formats
  • Excel
  • PDF
Data import formats
  • CSV
  • Other
Other data import formats

Data-in-transit protection

Data protection between buyer and supplier networks
Private network or public sector network
Data protection within supplier network
  • TLS (version 1.2 or above)
  • Legacy SSL and TLS (under version 1.2)

Availability and resilience

Guaranteed availability
Horizon service availability is calculated as:
Total number of minutes in the measurement period – Unplanned Downtime x 100 / Total number of minutes in the measurement period
Note: If a Service is partially available then the Unplanned Downtime shall be calculated in equal proportion i.e. if a service is 50% available then the unplanned downtime will be calculated as 50% x elapsed period of the incident.
Availability Measurement Period: 1 Calendar month
Target Service availability for Horizon is:
Horizon Graphical User Interface (GUI) is 99.9%
Horizon user subscriptions is 99.5%
Horizon Auto Attendant, Call Recording, and Unified Messaging subscriptions - 99%
Mean Average PESQ Score target of 4.1 for G711 and 3.7 for G729.
Not included:
- Outages which are deemed by us to be the result of matters outside of direct control
- Planned or emergency maintenance
- User error
Notes:Core functions are Gamma Switching infrastructure, transmission equipment and
core network, the service that supports call routing and termination.
Non-Core functions include Gamma Support Systems, access to any relevant portals and feature based services such as Call Plans, Call diverts, Auto Attendant, Call Recording, and Unified Messaging
PESQ score target for G711 is 4.1 and G729 is 3.7
Approach to resilience
Available on request
Outage reporting
A public network status dashboard
Email alerts
Portal alerts
Text messages to opted in mobile numbers
Service desk verbal communication

Identity and authentication

User authentication needed
User authentication
Username or password
Access restrictions in management interfaces and support channels
Relevant only to SIP Trunk call manager services. Customer administrators can set permissions for other users to give them access to certain areas of the portal. They are able to restrict access to certain areas of the management and support interfaces.
Access restriction testing frequency
At least once a year
Management access authentication
Username or password

Audit information for users

Access to user activity audit information
Users contact the support team to get audit information
How long user audit data is stored for
At least 12 months
Access to supplier activity audit information
Users contact the support team to get audit information
How long supplier audit data is stored for
At least 12 months
How long system logs are stored for
At least 12 months

Standards and certifications

ISO/IEC 27001 certification
Who accredited the ISO/IEC 27001
Lloyd's Register Quality Assurance Ltd
ISO/IEC 27001 accreditation date
What the ISO/IEC 27001 doesn’t cover
Not applicable
ISO 28000:2007 certification
CSA STAR certification
PCI certification
Other security certifications
Any other security certifications
Cyber Essentials

Security governance

Named board-level person responsible for service security
Security governance certified
Security governance standards
  • ISO/IEC 27001
  • Other
Other security governance standards
Cyber Essentials
Information security policies and processes
Nexus hold and maintain an Information Security Policy. We have an Information Security Office (ISO) who is responsible for the development, management and enforcement of the policy across our organisation.

Operational security

Configuration and change management standard
Conforms to a recognised standard, for example CSA CCM v3.0 or SSAE-16 / ISAE 3402
Configuration and change management approach
Nexus have a configuration management process for tracking changes in the specification of our services and products, this is managed centrally. Nexus also implement a full change management process for assessing and if appropriate executing any changes to services and products.
Vulnerability management type
Conforms to a recognised standard, for example CSA CCM v3.0 or SSAE-16 / ISAE 3402
Vulnerability management approach
We use failure mode effects analysis process, conducting regular, systematic assessments of vulnerabilities to determine the necessity of safeguards, countermeasures and controls, monitoring for changes to maintain an acceptable level of risk. Includes identifying key information assets and subjecting them to specific risk assessments, assessing exposure to a list of common threats and vulnerabilities, maintaining risk registers, implementing technical, policy, business continuity and management initiatives;
Each patch is assessed and deployed accordingly:
High - Urgently.
Medium - ASAP.
Low - as time permits.
Gamma utilise many Vendor sources and industry RSS feeds, CERT, Ubuntu and Debian. Member of CiSP.
Protective monitoring type
Conforms to a recognised standard, for example CSA CCM v3.0 or SSAE-16 / ISAE 3402
Protective monitoring approach
Gamma utilise GPG 13 guidance. Gamma have built a Security Information & Event Management Solution (SIEM) to identify potential compromises. If a compromise is found it is investigated. A Security Incident is raised to track the investigation, root cause and solutions if required to rectify or improve the situation. We respond to incidents as close to real time as practicable.
Incident management type
Conforms to a recognised standard, for example, CSA CCM v3.0 or ISO/IEC 27035:2011 or SSAE-16 / ISAE 3402
Incident management approach
All Incident tickets will be recorded in the Nexus Service Desk system under the Incident Management workflow. All new Incident tickets will undergo an initial impact assessment. Nexus will further look to determine the number of users/systems affected and establish the commercial impact to the customer’s environment. We have a knowledge base to be able to check for common events. Users can report incidents by phone, email or through their client portal. Incidents are included in any appropriate service monthly ticket summary reports.

Secure development

Approach to secure software development best practice
Independent review of processes (for example CESG CPA Build Standard, ISO/IEC 27034, ISO/IEC 27001 or CSA CCM v3.0)

Public sector networks

Connection to public sector networks
Connected networks
  • Joint Academic Network (JANET)
  • Health and Social Care Network (HSCN)


£6.19 a user a month
Discount for educational organisations
Free trial available

Service documents

Request an accessible format
If you use assistive technology (such as a screen reader) and need versions of these documents in a more accessible format, email the supplier at Tell them what format you need. It will help if you say what assistive technology you use.