| Carrier Ethernet: the story so far - Growing enterprise acceptance - Interoperability pains - Service IOT certification underway - More high-end CPE devices needed - Engineer/customer perception gaps on SLAs - QoS the top issue with customers |
Carrier Ethernet is gaining traction among carriers and trust among the enterprise customers being targeted by managed Ethernet services, but the experience reported by carriers so far also highlights the technology's weaknesses.
For instance, a commonly cited technical issue with Carrier Ethernet among carriers is interoperability.
'The lack of interoperability standards for Ethernet services is a challenge for us because the service has to be consistent, interactive and manageable regardless of where it is,' says Kaman Sistanizadeh, CTO and co-founder of global Ethernet service provider Yipes Enterprise Services.
Other interoperability challenges include support for jumbo frames, VLAN tag assignment and SLA system reports, Sistanizadeh says.
Complicating things is the fact that some interoperability issues are making it challenging to overcome some of Carrier Ethernet's other limitations. One example is Carrier Ethernet's difficulties in scaling past 4,000 VLANs, says Wang Ching-sheu, DWDM and broadband access project manager of Chunghwa Telecom's Broadband Network Lab.
'Technologies like Q-in-Q and MPLS Layer 2 VCs can solve the problem but both have interoperability issues,' Wang says.
Wang says that Chunghwa Telecom, which offers both residential and enterprise Ethernet access services, found other weaknesses with Q-in-Q and MPLS in solving VLAN scalability.
'Q-in-Q has problems with things like MAC learning, single-subscriber QoS, subscriber control and network planning and provisioning,' Wang said. 'On the other hand, Layer 2 VCs on MPLS are expensive, hard to manage across equipment from different vendors, and too complex for offering an Internet access service.'
Wang says Chunghwa eventually settled on an in-house proprietary solution. 'There is still a lot of room to improve the current technology.'
IOT: now certifiable
Carrier Ethernet's interoperability issues extend beyond getting equipment from multiple vendors to work together. It's also a question of interoperability between different service providers, especially when the name of the game is end-to-end Ethernet connectivity on an international and even global scale.
'[Interoperability] is the key facilitator for consistent, end-to-end service between regions, nations and continents,' says Nan Chen, president of the Metro Ethernet Forum.
Indeed, the MEF is already running an interoperability certification program with Iometrix to that end, with the added twist that it's aimed not at equipment vendors but service providers. Under the three-phase program, carriers have to demonstrate in the field as well as the lab that their Ethernet services are compliant with any or all of the Ethernet Private Line (EPL), Ethernet Virtual Private Line (EVPL) or ELAN (multipoint networking) definitions from the MEF 9 specification.