Advanced SONET Features Rick Summerhill Director Network Research, Architecture, and Technologies Internet2 LHC Meeting 24 October 2006 FERMI Lab, Chicago, IL

Rick Summerhill Agenda Basic Ideas GFP VCAT LCAS Control Plane

Rick Summerhill Framing and Network Layers Distinguish between network layers and framing Ethernet and SONET framing is typically supported on DWDM equipment DWDM equipment typically doesn’t support layer 2 multiplexing, although it does support such framing An Ethernet switch supports layer 2 networking, including statistical multiplexing A SONET TDM switch supports layer 1 capabilities, and using GFP, Ethernet framing

Rick Summerhill SONET Framing

Rick Summerhill Basic SONET Ideas SONET and SDH Channels Synchronous Payload Envelopes (SPEs) Table of control bits in SPEs STS-1 Channels in SONET Circuits like OC-3c, OC-12c, OC-48c, and OC-192c An OC-48c is 48 SPEs with control bits set to indicate the payload types In classic SONET OC-48c, these are all contiguous SPEs starting at boundaries of 0, 48, 96, 144 SPEs This is limiting - end up with “holes” in the SONET payload An OC-192c is different than an OC be carefull on ordering Sometimes called standard contiguous concatenation

Rick Summerhill GFP - Generic Frame Protocol Embedding frames into SONET payloads Note: Supporting 1 GigE would have required an OC-48c in classic SONET Not very efficient with classic SONET Two encapsulation techniques: Frame mapped (GFP-F): map frames (for example, Ethernet), to SONET frames Transparent mapped (GFP-T): Map bytes from frame to SONET frames Supported for a number of protocols: fiber- channel, Ethernet, etc.

Rick Summerhill VCAT - Virtual Concatenation Scalability - SONET Pipes can be sized to match the data payloads Classic SONET would require an OC-48c to support a 1 GigE! Efficiency - Eliminates the need for holes! Compatibility - Only the ends need to support VCAT! Resiliency - By diversifying bandwidth paths, you gain resiliency! Allows for decoupling the interface bandwidth from transport bandwidth

Rick Summerhill VCAT - Virtual Concatenation VCGs - Virtual Concatenation Groups Eliminate the boundary requirement Eliminate the contiguity requirement Even down to the fiber layer Many details about ways to bundle STS-1s or STS-3s, etc - see the standards All this is determined by bits in the control fields Identification of VCG limits the differential delay to no more than 256 ms (roughly +/- around the globe).

Rick Summerhill VCAT - Virtual Concatenation

Rick Summerhill Ethernet and SONET Features Ability to map vLANs through SONET channels One vLAN might get mapped out in one direction A second in a different direction Many issues in supporting 10 GigE over SONET even though they use the GFP protocols Dropping pause frames Buffering Need to test Ciena, Nortel, Alcatel compatibility

Rick Summerhill LCAS - Link Capacity Adjustment Scheme Protocol to synchronize the re-sizing of VCAT channels VCAT is independent of LCAS, but LCAS requires VCAT LCAS uses the H4 POH byte VCAT is really labeling, but LCAS requires a two way handshake Handshaking for downsizing Handshaking for upsizing LCAS doesn’t really do this, rather it supports the appropriate hooks, but it requires a control plane to implement

Rick Summerhill Control Plane Two basic standards: ASON (ITU) and GMPLS (IETF) Control planes do routing, path computation, etc. Different approaches - layered vs overal GMPLS doesn’t support inter-domain capabilities (DRAGON is an NSF funded project to investigate) OIF has influential recommendations to use E- NNI from ASON, and has provided direction There is much work left to be done in this space!

Rick Summerhill