Services | 4 min read

With A10 Networks, ngworx.ag resolves Leucom’s IPv4 addressing issues

The Leucom Group, headquartered in Frauenfeld and with its own cable and fiber optic networks, is one of the largest providers of Internet Service Providers in Eastern Switzerland with 18,000 Internet customers. And as IT leader Christoph Tobler notes, Leucom has the same problem that makes life difficult for many ISPs: "We are slowly coming to an end with the IPv4 addresses. You will no longer receive any new address blocks from the responsible contracting authorities." It would be possible, Tobler said, to buy free addresses on the market - but the prices are exorbitant. Also, the acquisition of a company that still has free IPv4 addresses, was out of the question.

A10 Networks
Carrier & ISP Networking

Carrier-grade NAT solves address problem
Leucom has concluded that Carrier-Grade NAT (CGN) brings the optimal solution: the provider no longer assigns a public but a private IPv4 address to its customers. A CGN gateway at the provider translates this private address into a public one for access to the Internet, with several customers sharing one of the rarer public addresses. Looking for the best possible CGN solution, Tobler first looked at the environment of a partner who had implemented CGN with their existing network infrastructure.

In further research, the IT director came across the CGN gateway Thunder CGN from A10 Networks. «This product convinced me. The manufacturer focuses entirely on CGN and other specialized technologies such as Application Delivery, DDoS Protection and IPv6 Transition – it is not about a general network provider that enables a little CGN along the way.»


High-performance CGN infrastructure
“The A10 distributor Boll responded to our request very quickly – we got a good presentation and could clarify everything necessary in an open discussion. The chemistry has been right from the beginning, “says Tobler enthusiastically. A proof-of-concept, realized with a test device together with the reseller ngworx and the experts from A10 Networks, has completely convinced Leucom that A10 was the right choice. The first contact with BOLL and ngworx took place at the beginning of 2017. Afterwards, everything ran at top speed: by the end of March, 3000 customers had already migrated to the new CGN environment. The speed of implementation has also surprised ngworx.

Business Development Manager Noam Suisa says: “All project partners agreed immediately. We are delighted that this project was completed quickly and efficiently.» Leucom made the transition gradually, starting with the lowest-priced subscriptions launched at the end of 2016. Christoph Tobler: «We started slowly, first with 100, then with 500 customers per week. Between 100 and 200 customers share a public address. So we could get feedback and check customer satisfaction.»

ngworx team The chemistry with the distributor BOLL, the manufacturer A10 and the reseller ngworx.ag has been right from the beginning. Christoph Tobler Head of IT, Leucom-Gruppe

There were problems with less than one percent of migrated customers. Most of them did not notice anything about the changeover. This was also the clear goal of Leucom: “We feel obligated as a provider that the CGN migration runs absolutely transparently for the customers and no handicap arises.” According to Christoph Tobler, a few small problems were already solved in the first test with ten customers, including himself.

A round solution. Because: The complete migration to IPv6 with its extensive address space would indeed solve the IPv4 scarcity problem. According to Christoph Tobler, however, this would not be opportune for Leucom: “The changeover would be very complex, and we could not yet implement everything we need with the current possibilities.”


High-performance CGN infrastructure
Leucom currently operates two Thunder CGN units. Should one fail, the other takes over the routing of the defective unit in the short term. The appliances are located in Zurich, where the connection of their network to the Internet backbone takes place. For the future, Leucom plans a third device at the Frauenfeld site. However, this would not be necessary for performance reasons: At the moment, the CPU load of the appliances is just five percent. According to the A10, a Thunder CGN appliance can handle as many as 15,000 customers – so Leucom can easily grow until its existing CGN gateways reach their performance limits. And with the other features of the Thunder CGN platform, which Leucom has not yet used, the provider is well prepared for a future migration to IPv6.


A10 Thunder CGN – high-performance Carriergrade NAT
A10 Networks’ provides with the IPv4 Scaling and IPv6 Transition technology Thunder CGN a superior, high-performance, carrier-grade networking platform from IPv4 to IPv6. Flexible carrier-grade NAT and other innovative features make it possible to extend the lifecycle of the IPv4 infrastructure and provide time to prepare carefully for the IPv6 transition.



At the Thurgau Internet provider Leucom, the IPv4 addresses are scarce.


A high-performance carrier-grade NAT solution makes it possible to wait with the costly and complex transition to IPv6.


  • Carrier-Grade-NAT with industry-leading performance and scalability
  • Access from IPv6 clients to IPv4 content
  • IPv4- und IPv6-tunneling
  • Application Layer Gateways for protocols such as PPTP, SIP, DNS, H.323
  • Comprehensive logging
  • Industry-leading performance per rack unit
  • Ready for Network Function Virtualization (NFV)

About Leucom

Founded as a radio / TV business more than 50 years ago, today Leucom is a broad-based multimedia group with more than 80 employees, based in Frauenfeld and branches in Schlieren and St. Gallen. Leucom builds and operates its own cable networks as a triple player (TV, telephony and Internet) and is rapidly advancing the expansion of fibre optics. The retail offer includes a range of internet and combi subscriptions with TV and telephony. Approximately 25,000 households, from Aargau to Appenzellerland, receive TV services and around 18,000 their Internet connection from Leucom. Business customers benefit from additional services such as virtual telephone exchanges and web hosting.

About A10 Networks

A10 Networks enables organizations to accelerate, secure and optimize the performance of their data centre applications and networks. A10 Networks was founded in 2004 and have pioneered a new generation of application network technologies. A10’s portfolio covers application delivery controllers, DDoS protection, DDoS attack mitigation, load balancer and next-generation firewall solutions. ngworx became an A10 Networks Gold Partner in 2017 and provides solutions for the service provider and enterprise market.

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