ccnxcon2012: session 4: caesar: a content router for high speed forwarding

COPYRIGHT © 2011 ALCATEL-LUCENT. ALL RIGHTS RESERVED.

Caesar: a Content Router for High Speed Forwarding

Matteo Varvello, Diego Perino, Jairo Esteban

Bell Labs, Alcatel-Lucent CCNxCon2012, September 13th,2012, Sophia Antipolis


Forwarding Information Base

FIB performs component-wise longest prefix matching Interest names -  e.g. ccnx://BellLabs/ICN/talks/reality.avi/chunk0 (B=5 components)

• Hardware-based approaches (TCAM)

•  Software-based solution

-  Multi-bit tries

-  Bloom filter

DRAM RLDRAM

SRAM Bloom filters

Prefix hash-table


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AGENDA

Rationale

Design

Evaluation

What s next?


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Rationale

Longest Prefix Match (LPM) should be as much independent as possible from the length of content names

Number of components, and character per component

Distribute the forwarding table across line cards to maximize size


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Design – LPM – Distributed Bloom Filters (DLB-BFs)

IPv6 Lookups using Distributed and Load Balanced Bloom Filters for 100Gbps Core Router Line Cards. Haoyu Song, Fang Hao, Murali S. Kodialam, T. V. Lakshman INFOCOM 2009


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Design – LPM – Distributed Bloom Filters (DLB-BFs) K DLB-BFs independently of the prefix length Map each content prefix to K bits, independently of the number of characters per component Perform B*K hash functions in parallel

Dimension system for high Bmax*K (hardware limits) Avoid slow LPM for long content names via prefix expansion


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Design – Distributed Packet Processing

h(comp1)modN


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Results – Single Line card Xilinx Virtex-6 and NetFPGA 40G board ; Bmax=128, T=64


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Results – Whole Router


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What s next?


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Questions?


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Hardware-based approaches (TCAM)

Software-based solution


-  Bloom filter

DRAM RLDRAM

SRAM Bloom filters

Prefix hash-table


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66Mps = half of the LPM operation rate performed today by each line card of a core router

10 Milion prefixes=2% of today s globally unique and routable hostnames


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Numerical Evaluation

Reference design is Xilinx Virtex-6 and NetFPGA 40G board

On-chip memory

34Mbit with up to 1,064 2-port SRAM blocks (32Kbit)

Off-chip memory

216Mbits SRAM

2.3Gbit RLDRAM

We divide the 1,064 2-port SRAM blocks across 8 DLBBFs

Each DLB-BF is composed by 64 SRAM blocks (64Kbit)

A 2-port SRAM block stores the LT

We generate 128x8=1,024 hash functions

Bmax=128,T=64


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Design – Linecard Details

h(comp1)modN ; h=CRC-64

If(B>Bmax)

Prefix Expansion


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Conclusions FIB design is a challenge for Information-Centric Networking

We design Caesar, a Content Router for High Speed forwarding

Distributed packet processing

LPM implemented with distributed Bloom filters

On-going and future work

Hardware implementation

Extension to software router


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Named Data Networking – Content Router

•  CS (Content Store) is the same as buffer memory of an IP router but can store a Data packet after it has been forwarded (caching).

•  PIT (Pending Interest table) keeps track of forwarded Interests. Only one entry per similar requests is kept.

•  FIB (Forwarding Information Base) is used to forward Interest packets toward potential sources using LPM lookup.

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A Reality Check for Content Centric Networking. Diego Perino and Matteo Varvello ICN2010 (Also published in CCR, October 2011)


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• Hardware-based approaches (TCAM)

•  Software-based solution


-  Bloom filter

DRAM RLDRAM

SRAM Bloom filters

Prefix hash-table

ccnxcon2012: session 4: caesar: a content router for high speed forwarding

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