— UAE Etisalat Constructing Multi-Service IP Bearer Network

Background

Founded in 1976, UAE Telecom Corporation Company, Etisalat is one of the leading operators in the Middle East and one of the global 500 corporations. Etisalat is well known in the industry for its innovative spirit, leading telecom services, excellent services, and good profits. It possesses an advanced telecom network, which covers more than ten countries. Its services cover fixed-line phone, mobile phone, Internet access, and cable TV.

Along with the emerging NGN, 3G, VPN, Triple-Play, and other new services, the number of subscribers keep increasing. The IP bearer network of the original single Internet service access could not satisfy the increasing requirements. On one hand, the capacity of the original equipment was insufficient. It could not satisfy the bandwidth requirements of fast increasing subscribers or well support the future expansion. On the other hand, the original network lacked capability in multiple aspects such as MPLS VPN, high reliability, QoS, multicast, and IPv6. In general, it was unsuitable to bear the carrier-class services. Early in 2004, Etisalat was aware of the previous problems. To take the preemptive opportunities in the future new service market, Etisalat decided to reconstruct and upgrade the original core IP network so that high-value services could be borne in a unified manner. Etisalat also stressed the network as the future service development.

At the end of 2004, Etisalat performed strict tests, including outdoor test and multi-service simulation and emulation on the equipment and solutions of various vendors. After half a year of testing, Etisalat formally announced that the network has to be upgraded and expanded by using the IP bearer network solution recommended by Huawei in April 2005. The Quidway® NetEngine 40E (NE40E) High-End router was applied to construct the network core. In addition to the existing Internet and mobile IP services, the network would provide NGN, Triple-Play, IPTV, and other new services.

Solution

In considering the current network status, future service planning and original network investment protection, Etisalat adopted the multi-service IP bearer network solution as shown in the following figure:



Carrier-Class Reliable Network with Continuous Service Providing

As the platform for the future Etisalat multi-service development, the IP bearer network possesses the undoubted importance. Once errors occur on the core equipment or routing layer, the quality of service (QoS) of the entire network is affected or even a large quantity of services are interrupted. The longer the services are interrupted, the greater the loss is brought to the operator. Thus, Etisalat pays great attention on constructing a highly reliable bearer network.

Reliable equipment is the foundation of the network reliability. The core equipment NE40E of this solution adopted the passive backplane design. All the components supported hot swap and the redundancy backup of key components such as route processing module, switching network, power and fan. The hot patch technology was supported to implement the complete smooth upgrading of the software. More importantly, the GR that support multiple routing protocols such as OSPF, IS-IS, BGP, and LDP was adopted, and the non stop forwarding (NSF) technology was realized. This was to ensure that even failure occurs on the control layer, the services could still be forwarded uninterruptedly during the equipment restart.

The equipment reliability was only a single-point technology. The problems of network reliability could be solved by depending on key reliability technology instead of simply stacking multiple sets of equipment. The highly reliable IP bearer network solution should realize the fast fault detection, protection switching and network self healing. NE40E supported various fault detection and protection switching mechanisms such VRRP, IP/LDP fast rerouting, RPR self-healing ring network. In Etisalat IP bearer network solution, NE40E together with other core equipment deployed the MPLS TE FRR, LDP over TE, IGP fast convergence and other highly reliable technologies in a unified way. In the subsequent stage, technologies such as BFD and OAM were deployed to reduce the link fault detection duration and to improve the network reliability.

By deploying the reliability technology on multiple layers such as device, link, and network, the Etisalat ensured the high-speed running of the entire network services and achieved the carrier-class reliability of 99.999%.

Good Compatibility and Expansibility to Protect the Investment

Etisalat is one of the largest operators in the Middle East. To reduce the commercial risks of the network construction, it was certain that Etisalat would introduce equipment from different vendors. In this case, there was already equipment of multiple venders in the original Etisalat network. As a result, the equipment compatibility of these venders became a main concern of Etisalat. As the PE equipment, the NE40E should connect to the core P equipment in the uplink direction and converge various types of CEs and terminals in the downlink direction. Thus, it raised a high requirement on the interconnectivity. After repeated stringent online interconnection tests, the NE40E showed good interconnectivity in the aspects of physical interface, protocol, function, and service. The test result completely removed the worries of Etisalat. In upgrading and deploying the dual service access platforms, the original core routers and convergent switches could still be uses as the core and convergent equipment of the Internet service access. This was to protect the original investment and reduce the network construction risks to a maximum extent.

In addition, NE40E could provide 10G interfaces and supported the full duplex wire-speed forwarding of the 10G interface. In the subsequent stage, it could also provide high-density 10G or even 40G interface. In the existing network, Etisalat mainly adopted the high-density 2.5G POS link. In the future, Etisalat would satisfy the requirements raised by the fast increasing subscribers and services to provide high-quality services for subscribers.

Simplifying Network Layers and Reducing CapEx and OpEx

Flat network can facilitate operators to provide high-quality services for subscribers and to swiftly deploy the network maintenance and services. As the core router, NE40E converged the features of Ethernet switches and provided the FE, GE and 10GE switched Ethernet boards. It possessed rich layer-2 features, including VLAN, QinQ and MSTP. It could also deploy the distributed VPLS services. The switched Ethernet boards could provide much higher port density and reduce the pressure on the port number of NE40E as the PE router. More importantly, the Ethernet switches and NGN devices could directly access the NE40E switched Ethernet interface and simplify the service access layers to make the network develop in the flat direction.

The diverse L2 features of the NE40E brought about many benefits to Etisalat. Currently, in most sites of Etisalat, the NGN equipment and the DSLAM directly accessed the NE40E. In this way, it was free from deploying the L2 switches in the convergent layer and it reduced the CapEx. Meanwhile, due to the simplified network layer and reduced service provisioning time, the network maintenance and fault location was facilitated and the OpEx is reduced.