Tesseract A 4D Network Control Plane

Carnegie Mellon University Microsoft Research Rice University Presented by: Alberto Gonzalez, Whitney Young. Tesseract A 4D Network Control Plane. Current Designs. No direct control Subtle dependencies

Carnegie Mellon UniversityMicrosoft ResearchRice UniversityPresented by: Alberto Gonzalez, Whitney YoungTesseractA 4D Network Control PlaneCurrent Designs

No direct control

Subtle dependencies

Example: load balance forwarding by tuning OSPF link weights, but impacts inter-domain routing

Services:DisseminationNode configuration4D ArchitectureControl plane:

Decision

Dissemination

Discovery

Data

DesignDesign Goals

Timely reaction to network changes

Resilient to decision plane failure

Robust and secure control channels

Minimal switch configuration

Backward compatibility

Support diverse decision algorithms

Support multiple data planes

Implementation Overview

Switch

Implements data plane

Decision Element (DE)

Implements discovery, dissemination, and decision planes

Decision Plane

Any network control algorithm can be easily integrated

Incremental shortest path first

Spanning tree

Joint packet filtering/routing

Link cost-based traffic engineering

Resiliency to DE failure

Hot standbys receiving heartbeats

Dissemination Plane

Goal: communication between DEs and switches

DEs handle most of dissemination plane, but switches help out

Path to destination handled by DE

Switches have separate queue and dissemination packets have higher priority

Security (protects switches, info passed through dissemination plane, and compromised DEs)

Discovery Plane

Goal: minimize manual configuration

Switches send HELLO messages

DEs handle instructing the switches on what to do once active

Initiate eBGP session with outside world

Backward compatibility (bootstrapping end hosts)

Discovery plane as DHCP proxy

Data Plane

Configured by decision plane

WriteTable exposed with simple interface to provide configuration service to decision plane

Allows easy implementation of different services

Decision/Dissemination Interface

Function independently of each other

Only 3 functions used to interface between them (2 more simply to improve performance)

Switch& Regional Failures Performance Evaluation

Single Link Failures

Link Flapping

10-hop to 12-hop change

Tesseract can handle network changes

Performance Evaluation

1347 nodes & 6244 edges

DE Computation Time

Worst Case: 151ms

99th percentile: 40ms

Bandwidth overhead

Worst Case: 4.4MB

90% of switched updated with new state

Performance Evaluation

Failover times

Applications

In enterprise network:

Computers both new routes & packet filter placements

Loads into routers with no forbidden traffic leaked

No human involvement once security policy is specified

Ethernet

Key features

Widely implemented frame format

Support for broadcasting frames

Transparent address learning model

Tesseract keeps these properties.

Ethernet

Through point comparisons

Control Plane for TCP flows

Started at 570Mbps

Leveled at 280Mbps after a failure

Conventional RSTP Control Plane

Starts at 280Mbps

Hit zero after failure

Recovered after 7-8 seconds at ~180Mbps

Summary

Tesseract

Robust

Decission/Dissemination Planes

Secure

Enterprise Network

Resuable

Ethernet or IP

Good Performance

Convergence & Throughput

Scalable

1,000+ Switches

Enables direct Control

Easier to Understand and Deploy