Interconnecting the dots

What we do
Who we are
Out & Inbound
Video Alliance

What we do

GCXS offers multimedia interconnection services that resolve the challenges of next generation interconnection by facilitating seamless interworking and interoperability between multiple IP networks.

GCXS is a rapidly growing Dutch company at the forefront of changing the communications landscape.

GCXS enables its customers to capitalise on their network and technology investments through the delivery of IP voice, video and unified communications (UC) across different networks and platforms.

GCXS provides a suite of interconnection products and services enabling Service Providers (SPs) to:

  • Deploy advanced NGN services which operate across SP boundaries;
  • Minimise the cost of NGN interconnection;
  • Increase cross network NGN service quality and reliability.

Our services are provided in partnership with XConnect from the UK.

XConnect is the world's leading provider of next generation interconnection services driving the adoption of IP based multimedia communications and are powered by an award winning ENUM registry and IPX hub technology.

Who we are

The GCXS Dutch Interconnect Alliance (DIA) service is a set of network capabilities and product features which facilitate interconnection between Next Generation (NGN) Service Providers (SPs) to enable the exchange of ‘VoIP’ (and other ‘media over IP’) traffic.

Global Communication Access is head quartered in Waddinxveen, Netherlands.

Customers include major carriers, Service Providers, Unified Communications, and Video Conferencing providers.

GCXS partners with XConnect

Dutch International Alliances

Bi-Lateral Interconnect Issues

The DIA service of GCXS enables NGN SP customers to realise the benefits of providing cross network advanced VoIP services, whilst minimising the effective cost of interconnection compared with the direct bi-lateral model. This is shown below:

The DIA service is a multi-lateral interconnect model (also known as Federation). Customers connect their NGN network (IP interconnect and SIP interconnect) to the DIA service , and can then send and receive VoIP traffic to/from any other connected network on a ‘policy’ basis.

DIA will support a number of product features, allowing customers to select the best interconnect service (in terms of traffic types supported, quality of service requirements, settlement models etc.) to suit their business. The DIA service is designed to carry advanced VoIP services, and to provide carrier class availability and traffic performance required for business critical commercial services.

The DIA network described above is used to create a number of different interconnect products. Customers can subscribe to one or all of the DIA products depending on their business requirements.

DIA products will be rolled out over time, based on customer demand, and GCXS are happy to hear from customers where additional products or features would be beneficial. Initially the following products will be available :
  • Dutch National Alliance – A public interconnect Community of Dutch national service providers, for exchanging Dutch on-net national traffic.
  • Dutch Private Alliance – A product allowing a Service Provider to create their own interconnect Community with selected partners to terminate any traffic types.
  • International Outbound – A to Z PSTN termination via the XConnect Global Alliance network.
  • International Inbound – Termination of XConnect Internationally Originated traffic into the Dutch and other transit markets.

Dutch National Alliances

The Dutch National Alliance (DNA) product enables multi-lateral peering of Dutch National traffic between on-net Dutch Service Provider members. The DNA service is a peering service, therefore the following rules apply:

  • Only Dutch licensed operators with telephone numbers issued by ACM can become members;
  • Traffic is only allowed between on-net numbers (i.e. no transit traffic) owned by the members (i.e. either allocated by ACM or ported-in);
  • Members must terminate all calls to their own TN's, and all TN's must be available;
  • Traffic will generally be expected to balance over time;
  • Members can decide to opt-out of peering with specific other members;
  • Members can choose either settlement free, or GCXS will settle for the interconnect traffic.

Dutch Private Alliance

The Dutch Private Alliance allow Service Providers to create their own private interconnect community where the owning SP determines the policy, routing and settlement rules. The Dutch National Alliance (DNA) product only allows calls to be exchanged between on-net Dutch telephone numbers.

Our hub

The interconnect hub is the central point for interconnecting SIP Signalling and Media between DIA customers. SPs connect their VoIP network to the Interconnect Hub and can pass calls to all other connected SPs, avoiding the need to implement multiple direct VoIP interconnects. The Interconnect Hub queries the Registry to determine whether a particular call between SPs is ‘allowed’ through policy and if so where to route the call. The Interconnect Hub provides the following functions:

  • Session Border Control – All SP SIP interconnects to the hub terminate on the interconnect hub SBC. The SBC supports SIP layer security (topology hiding, Call Admission Control, B2BUA, SIP message validation), and SIP interworking (allowing different implementations and methods of SIP to be ‘interworked’ amongst the SPs);
  • Stateful SIP Proxy – The SIP Proxy routes the SIP messages between the SPs. The proxy's internal routing engine queries the Registry to determine whether a call is allowed, and the appropriate SIP route for the call. The SIP Proxy routing engine supplements the routing data received from the Registry to allow more complex routing scenarios if required (eg first choice, second choice etc.). If a call requires Media Relay, the proxy will allocate an appropriate address and port;
  • Media Relay – The media relay is an optional element, and can be used to support particular call scenarios where media topology hiding or NAT traversal are required. Use of the media relay for a particular call is controlled by the SIP Proxy;
  • CDR Generation – A Call Detail Record is generated for every call across the hub. CDRs are stored in a data-warehouse and form the basis for quality and usage reporting for the DIA services. For Federations utilizing the platform settlement option, the CDRs also form the basis of all inter-provider settlement charges.

International out & inbound

Via our partner XConnect, GCXS can offer Dutch Interconnect Alliance customers an International Outbound service which terminates traffic via XConnects International Global Alliance network. This product uses XConnect’s direct peering routes to SPs across the world combined with the XC Registry to provide high quality, low cost VoIP termination. The International outbound product is sold on a traditional per minute per destination basis using a rate sheet which will be provided to customers and updated from time to time. Conversely, GCXS would like to terminate traffic from XConnect International customers via the DIA network. This may be to Dutch customers own TNs only, or other national or international transit routes.

Interconnecting to DIA

The following section describes the general technical requirements for an SP wishing to interconnect to the DIA service. As part of the service implementation, GCXS will work with customers to exchange interconnect design information, and conduct interoperability testing. Connecting to DIA requires the following:

Interconnecting at the IP level to the DIA IP network.

  • Interconnect may be via Private IP or via the Public Internet.

Interconnecting at the SIP and RTP media layers to the DIA Interconnect Hub

  • SPs need to establish at least one SIP trunk from their NGN network to the DIA interconnect hub (deleted because is confusing). Generally this would be from the SP SBC (or other border element);
  • The SPs can establish multiple SIP trunks from diverse border elements if required for resilience;
  • SPs need to authorise RTP media to be sent from the DIA RTP source addresses. (eg within the SP firewall or SBC);
  • All SIP/RTP IP addresses and common SIP parameter settings will be exchanged as part of the interop process.

Product Selection.

  • The DIA SP will indicate (and sign the appropriate contracts) which products they wish to belong to.

Establish Outgoing Routing Scheme

SPs will need to determine how to route outgoing national traffic via DIA instead of routing via the PSTN. A list of DIA members (in each Federation ??? why multipal federations?) will be available via the DIA portal. The SP has three options for outgoing routing:

  • Internal Routing with Internal NP data – Where the SP has a sufficiently capable internal routing engine, the SP can use the Dutch NP database to support NP corrected routing to route calls via the DIA Exchange service to those on-net Member TNs only;
  • Send ‘All Calls’ – the Originating SP can send all calls (or specific known ranges) to the DIA Hub. Calls which cannot be terminated will be rejected by DIA with the appropriate SIP response, and the SP can ‘route advance’ the call to their second choice carrier;
  • DIA Registry Edge Query – the Originating SP can do an ‘All Call Query’ (ACQ) against the DIA Registry, the Registry will return the DIA Exchange SIP address if the call can be terminated via the DIA service. The query may be SIP Redirect or ENUM. If the call cannot be terminated via the DIA service a suitable ‘not allowed’ response will be returned and the Originating SP can ‘route advance’ the call to their second choice carrier. This method has the following advantages :
    • The SP’s internal routing system is less complex, as it doesn’t have to integrate NP data;
    • An All Call Query uses less switch resources than sending all SIP calls to the DIA Exchange hub;
    • As new SPs are added to the DIA Exchange product, the SP does not have to modify their outgoing routing plan.
  • Billing and Reconciliation – Depending on the product, the SP needs to consider any impacts on internal billing and reconciliation systems for the end-to-end traffic.
    • Customers will be able to access the DIA portal to get reports on traffic usage and performance (and CDR detail) to understand the volumes and flows of traffic with other Members.

Video Alliance

The Dutch Video Interconnection Alliance (DVIA) is a carrier-neutral, multilateral Video Federation that securely interconnects disparate video networks.

DVIA streamlines the technical and commercial aspects of interconnecting to multiple video networks to provide seamless cross-network video conferencing and calling. Once connected, Video Service Providers (MSP) gain access to an ‘interconnect toolkit’ of technical and commercial functions . This service will be live at the end of 2013.