Netdev 1.2 Day I

The first day of the Netdev 1.2 Conference in Tokyo! We were attending the following talks:

Practical Guide to Run an IEEE 802.15.4 Network with 6LoWPAN under Linux

Stefan Schmidt presented the wireless solution for embedded devices oriented to IoT challenges like low battery and small RAM memory. 6LoWPAN is an IPv6 encapsulation for headers compression that permits the usage of optimized IPv6 on IoT networks.

Some tools used are linux-wpan and wpan-tools. RIOT is an operating system for IoT and Contiki is an alternative for linux+RIOT.

Implementing IPv6 Segment Routing

David Lebrun presented Segment Routing which is a new implementation that permits to have a shortest path through the intermediate nodes.

It’s required to encapsulate packets in ingress and egress stages, and the user space needs to be aware of the key used to identify packets.

Making Linux TCP Fast

Yuchung Cheng and Neal Cardwell (from Google) presented a new feature in the next kernel 4.9 to improve the TCP speed through reducing the retransmissions detecting the packets losses. They claim that buffering packets in queues improve delays and the retransmissions needed.

BBR (Bottleneck Bandwidth and Roundtrip propagation time) is a new module that seeks high tput with small queue size by probing BW and RTT sequentially. When the buffer is being filled, then drain and probe BW.

With BBR+RACK, Google improved speed 2-20x TCP WANs with higher bandwidth and lower latency.

Kernel TLS (Transport Layer Security) Socket

Dave Watson presented the TLS (or SSL) kernel implementation in order to reduce copies from/to userspace and hence improve performance. kTLS sendfile reduces CPU cycles 93/100.

The implementation needs 2 fds: TCP socket and AF_TLS socket.

In addition, Datagram TLS and KCM could be used in this implementation.

TLS Offload to Network Devices

Boris Pismenny (from Mellanox) presented HW offload solutions to get kTLS from 4.4 Gb to 8.6 Gb with HW offload.

KEYNOTE: Accelerating Service Delivery Using Linux Network Innovations

Damascene Joachimpillai (from Verizon) presented why a corporation like Verizon rely in Linux OS for their datacenters, although not currently for the carrier network.

They’re very interested in TC stuff.

TC extended workshop

Jamal Hadi Salim (from Mojatatu Networks) organized the TC workshop where several speakers talked about the evolve of such tool, mainly eBPF support.

Switchdev BoF

Jiri Pirko, Yotam Gigi and Matty Kadosh (from Mellanox) presented some problematic topics that they’re facing with the switchdev implementation.

Encapsulation Offloads LCO, GSO_PARTIAL, TSO_MANGLEID, and Why Less is More

Alexander Duyck (from Intel) explained by it’s important to calculate correctly the checksums and how to accelerate it with HW offload and such implementation for the most popular Intel network drivers.

VNIC offloads fact or fiction

Stephen Hemminger (from Microsoft) explained the research of different drivers and Linux Kernel infrastructure to provide Hyper-V hypervisor a high performance networking stack with Linux. A comparison of Virtual NICs drivers performance like virtio (Qemu), vmxnet3 (VMware), netsvc (Hyper-V) and Xen were shown.

Stacked Vlan: Performance Improvement and Challenges

Toshiaki Makita (from NTT) presented the implementation improvements, challenges and performance applied to stacked vlans since the last Netdev 0.1.



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