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Alibaba Says Large OTN Can Grow as They Do

4/8/2013 3:44:00 PM


Alibaba Group is China's largest and the world's second largest Internet-based company that operates diversified Internet-based business to facilitate easy online sales from anywhere in the world. At present, Alibaba's business reaches Internet users in more than 240 countries and regions around the world.

Key Challenges

Alibaba Group has set up many businesses and affiliated entities, such as Taobao Marketplace, Alipay,, and Alibaba Cloud Computing. Several major integrated data centers (IDCs) are responsible for the massive data services generated between the headquarters and subsidiaries, between subsidiaries, and between the subsidiaries and carriers, so IDC interconnection is critical. Here were the challenges below:

  • Fast and unpredictable service growth
  • Service bandwidth must be continuously increased to match unpredictable service growth (for example, when sellers promote various special offers in holidays, access and transaction volume increases sharply, requiring massive service bandwidth).

  • Fiber direct connections and increased network complexity
  • Since the optical interfaces of routers were directly connected to each other, the fiber connections between IDCs became increasingly complicated. Fiber cuts would interrupt services, and service interruptions would slow down user access speeds.

  • Leased fibers with high fault rate and poor controllability
  • When a fiber fault occurred, the maintenance department could only negotiate with the bandwidth provider to resolve the problem, which results in unpredictable fault resolution timelines and complicated maintenance work.


By using the existing IDC equipment rooms as service nodes, the new OTN nodes connected the headquarters with subsidiaries of Alibaba by leasing carriers' fibers. In the first phase, six IDCs were connected to this OTN network. In the second phase, the number of IDCs increased to 8. Huawei OTN solution has the following advanced features:

  • Large-capacity design to meet growing service demands and simplify the network
  • Huawei used OSN8800 devices to construct an 80-wavelength DWDM system. The transmission rate for a single wavelength can be upgraded to 10 Gbit/s, 40 Gbit/s or 100 Gbit/s. Services with up to 8 Tbit/s (80-wavelength * 100G) transmission rate can be scheduled on one pair of optical fiber. The solution not only reduced the leased quantity of optical fiber, but also considered the demands in several future years.

  • Flexible service grooming, convenient capacity expansion and rapid service launch
  • As to the service access and grooming, separated tributary-line architecture was used aiming at the uncertain time of flow pinnacle. This architecture means that access service is integrated and groomed by a unified cross-connection, and then redistributed to the specified circuit board for data transferring, which allows services on the live network to be unaffected during service expansion, line bandwidth upgrades, and network topology changes, as long as the related resources has been reserved. Capacity upgrade could be done on Alibaba's side, eliminating the need to to negotiate with carrier and facilitating greater control over fiber resources.

  • Increased network protection to improve the network robustness
  • WDM technology simplifies the physical fiber connections. Besides, ODUk level's subnetwork connection protection (SNCP) technology (dual transmission and selective receiving) is used to implement service switchover within 50 ms in the event of fiber cuts.

  • Customized O&M to ensure 24/7 troubleshooting
  • Huawei provides 24/7 maintenance services, ensuring quick response to network faults.

    In addition, Huawei's U2000 network management platform notifies maintenance engineers of network alarm information by SMS as soon as they occur.

Customer Benefits

Huawei provided a large-capacity OTN for Alibaba, featuring flexible services expansion capabilities, allowing them to keep up with growing service demands and speed up IDC deployment. In addition, the OTN simplified the fiber direct connection network structure by reducing the number of fiber links that couldn't be directly controlled, thereby reducing the network fault rate by more than 60%. Huawei offered excellent network protection capabilities and a customized network management platform, which ensured smooth operation of the network and services.