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Tiscali International Networks: Experiencing Real-World High Availability


Since installing Chiaro Network’s Enstara systems in its Amsterdam subsidiary in March 2005, Tiscali International Networks has experienced non-stop operation of the Enstara platform. Chiaro’s Enstara platform has enabled Tiscali International Network’s operations group to continuously maintain peering and live traffic during software upgrades without rebooting or interrupting network traffic. As a result, Tiscali has expanded the existing Enstara systems in Amsterdam and ordered additional Enstara systems in September 2005.

Tiscali International Network BV (TINet) is the backbone network subsidiary of Tiscali. It is a Tier-1 IP/MPLS network covering 15 European countries (more than 120 PoPs) plus the USA (six PoPs) as of Q4 2004, and it is still growing. TINet owns 12,000 km of fiber routes in Europe and controls an additional 40,000 km of fiber routes across the USA, along with two redundant transatlantic links. This large fiber network runs at 2.5 and 10 Gbps, on the top of which sits an IP/MPLS backbone (with AS3257).

TINet focuses on delivering leading-edge clear-channel, voice and IP-based turnkey solutions to carriers, xSPs (including Tiscali in its seven country networks) and multinational corporations. Supporting today’s largest European VoIP implementation, TINet is becoming one of the largest and fastest-growing carriers throughout Europe and will likely become independent over time.

Key network assets of TINet include the following:

• Wholly owned fiber backbone running DWDM for scalability.

• End-to-end MPLS-enabled IP network delivering traffic engineering and QoS.

• 200+ peering agreements, the largest ISP community for a European player.

TINet’s Network Evolution
In each of the 15 countries that it interconnects (including the seven Tiscali national networks), TINet has two interconnected routers that interface with each country’s national network. The traffic growth in some of these regional networks demanded an upgrade of the existing interconnection routers. Specifically, a new router upgrade was required to support 10 Gbit/s interfaces, and the existing core routers were not capable of supporting these speeds. Additionally, the existing equipment was nearing the end of its economic lifecycle, necessitating a technology refresh for the network.


Network Requirements Established
Being innovative, TINet didn’t see its situation only as an opportunity to expand capacity. TINet also wanted to install network equipment that could support higher classes of service and lower capital expenditures over a 5- to 10-year period. In November 2003, vendors were invited to offer their solutions in line with a well-defined “wish list” that was captured in a RFP/RFQ. The RFP/RFQ responses provided Tiscali with an overview of the available technologies, features, and potential commercial frameworks for a new technology implementation during 2004.

Some key requirements listed in the RFP were:

• Ability to support 10 Gbit/s Interfaces today.

* Ability to scale beyond 10 Gbit/s in the future.

• Cluster capabilities of the system.

• High-availability feature set — allowing for in-service upgrades.

• IPv4 and IPv6 — dual stack.

• Virtual or logical routers.

• Interoperability (with existing equipment and with network management software).

The Selection Process
Based upon the review of the RFPs, TINet learned that the big players’ cluster technology was not ready for prime time; hence they decided to postpone the final vendor selection. Postponing the selection gave the Tiscali technical team some time to research each vendor’s solutions and distinguish fact from fiction.

2004 was the year when Tiscali investigated in detail the solutions from the various vendors who had replied to the RFP. This investigation included Chiaro’s Enstara IP/MPLS platform. Throughout the year, Tiscali performed an extensive evaluation of the Enstara platform that included a visit to Dallas to perform tests at Chiaro’s lab as well as final stages of testing at Tiscali.

The last phase within the technical evaluation was a field trial in the Tiscali production network supporting connections between Frankfurt and Brussels. Protocols to support the live traffic included ISIS, BGP, IPv6 and MPLS. In February 2005, after forwarding 250 Terabytes of traffic over a three-week period, TINET chose the Enstara system for general network deployment as their core router of choice.

Chiaro’s Enstara Platform Shines
After an interactive year between Chiaro and Tiscali, the Tiscali management team reached some conclusions. All the “hard” items on the Tiscali checklist were addressed:

• Technology requirements: cluster, HA, interoperability, etc.

• Financially stable channel with ECI Telecom.

• 24/7 support structure and disaster recovery with ECI Telecom.

• Competitive price.

However, there was still a “soft” item to be resolved, which had to do with the selection of brand-new technology as well as a comparatively new supplier.

The Tiscali management team made some conclusions:

• Traditional vendors and their cluster technology were “as new” as the Enstara platform

• Only the Enstara platform was able to deliver, now, on the promise of real-world high availability.

• Responsiveness from the Enstara team was impressive and was not met by other suppliers.

• Tiscali’s track record of having a bullish approach to launching new, innovative services in the market justified an innovative network with state-of-the-art technology from a new kid on the block — just as they did several years ago with their previous router technology.

• Tiscali wants to have a choice beyond the traditional duopoly (i.e., Cisco and Juniper).

• Tiscali planned a phased introduction of the Enstara platform in its live network, leaving room for evaluation before continued expansion.

Tiscali put two Enstara systems into production in April 2005 at two different locations in Amsterdam. The regional Tiscali network in the Netherlands is expected to reach the 10 Gbit/s traffic mark during 2005, and therefore this network required the first transition to the Enstara platform.

Installations performed jointly by the Chiaro and ECI teams went smoothly. The two Enstara systems now carry all traffic in and out of the Netherlands for TINet. The displaced routers are re-deployed as edge devices in Tiscali’s network.

The Enstara systems are running several protocols, including BGP, ISIS, LDP, RSVP, IP, IPv6 and MPLS. The systems provide for connectivity to external peers, transit providers, direct customers and other vendors’ core site systems.

Chiaro’s Enstara Platforms Deliver Real-World HA
One of the main benefits for Tiscali of the Enstara platforms is their real-world high availability (proven in-service high-availability beyond 99.999).

Significantly, TINET has deployed several new Enstara features and enhancements by upgrading software — all during live operation, in service, without any downtime or network disruption. The key Real-world Enstara feature responsible for these “hitless” software upgrades is Chiaro’s STateful Assured Routing (STAR) technology.

Chiaro’s STAR technology is a unique embedded route processor protection mechanism that assures that router-to-router peering sessions are maintained during failure, switchover and software upgrades. This means that the Enstara router control plane is always up and running, under all circumstances, improving the reliability of the overall systems beyond 99.999 percent. STAR technology supports all routing protocols including unicast, multicast, and MPLS, and it moves well beyond the commonly used graceful restart paradigm in terms of effectiveness, speed, protocols supported and scale (i.e., number of routes supported).

TINet Expands its Enstara Commitment
The reliable operation of the existing Enstara systems in Tiscali’s Amsterdam facility, and the ongoing strong support of the Chiaro and ECI team, convinced Tiscali to increase its use of the Enstara platform. In addition, the ability to do hitless software upgrades has enabled Tiscali to “rethink” its network architecture and upgrade cycles.

Within a few months of its initial Enstara deployment, TINet expanded its Enstara technology in Amsterdam and in September 2005 ordered additional Enstara platforms for its operations.

The TINet upgrade has been triggered by a rapid increase of traffic handled by the national feeder networks. When these networks hit a certain threshold, it becomes clear that a transition to 10 Gbit/s oriented technology is required. The Enstara platform, after its successful introduction and operation at Tiscali, became the obvious choice for supporting this evolution. IT

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