Practical Chip Design

PMC-Sierra continues to be very positive on the gradual spread of the ITU-T G.709 Optical Transport Network (OTN.) The company sees OTN dominating the long-haul and Metro links that make up the invisible muscle and bone of the Internet. But PMC also expects an even further evolution: OTN from enterprise data centers and access routers, digital subscriber-line access multiplexers (DSLAMs), and wireless backhaul connections into the carrier Ethernet Switch and router (CESR) boxes.

"There is an opportunity for carriers to realize significant savings in operating expenses by spreading OTN across their equipment," said PCM director of marketing Babak Samimi. "OTN offers an environment optimized for mixed modes of packet traffic with a single, unified network management layer all the way through CESRs and even out to DSLAMs."

Following belief with investment, PMC some time ago introduced an OTN chip for Metro optical networks: HyPHY. This morning, they followed up with the logical next step: Meta 20G. This chip, intended for CESRs, provides 2 10Gbit flexible ports on its client side, a 20 Gbit Interlaken or dual XAUI port on its system side, and all the necessary PHY, MAC, SONET framing and mapping, OTN framing, and control functions necessary in between.

The concept is that the chip can bridge any combination of 10Gbit Ethernet, OC192 packet-over-SONET, and OTU2 (Optical Transport Channel Unit 2) traffic on the client side into the core of an OTN CESR box or packet optical transport platform. This will allow carriers to make a gradual transition from the Ethernet and SONET packet services they must support today to the OTU2 connections they could have tomorrow, without having to make continual hardware changes to their card inventory and continual adjustments to their management software.