Network Processor and Its Applications 1

1
Network Processor and Its Applications (1)

• Yan Luo yluo_at_cs.ucr.edu
• Prof. Laxmi Bhuyan bhuyan_at_cs.ucr.edu

2
Outline

• Overview of the network processors
• Networking protocol stack
• IP routing
• Packet Classification
• Other applications

3
What the Internet Needs?
ASIC (large, expensive to develop, not flexible)
Increasing Huge Amount of Packets Routing,
Packet Classification, Encryption, QoS, New
Applications and Protocols, etc..

• High processing power
• Support wire speed
• Programmable
• Scalable
• Specially for network applications

General Purpose RISC (not capable enough)
4
Typical NP Architecture
5
Network Architecture and Applications

• Introduction to networking
• IP packet structure
• Control and data planes
• Traditional applications
• IPv4 routing, classification etc.
• New applications
• URL-based switching,transcoding, etc.

6
OSI Network Architecture
Source Network Processor Tutorial in Micro 34 -
Mangione-Smith Memik
7
TCP/IP Model
Source Network Processor Tutorial in Micro 34 -
Mangione-Smith Memik

• ISO OSI (Open Systems Interconnection) not fully
  implemented
• Presentation and Session layers not present in
  TCP/IP

8
TCP/IP packet
Source Network Processor Tutorial in Micro 34 -
Mangione-Smith Memik
9
TCP/IP packet
Source Network Processor Tutorial in Micro 34 -
Mangione-Smith Memik
10
TCP/IP packet
APP. DATA
TCP
IP
MAC
MAC
Source Network Processor Tutorial in Micro 34 -
Mangione-Smith Memik
11
Application Categorization

• Control-Plane tasks
• Less time-critical
• Control and management of device operation
• Table maintenance, port states, etc.
• Data-Plane tasks
• Operations occurring real-time on packet path
• Core device operations
• Receive, process and transmit packets

Source Network Processor Tutorial in Micro 34 -
Mangione-Smith Memik
12
Processing Tasks
Source Network Processor Tutorial in Micro 34 -
Mangione-Smith Memik
13
Data Plane Tasks

• Media Access Control
• Low-level protocol implementation
• Ethernet, SONET framing, ATM cell processing,
  etc.
• Data Parsing
• Parsing cell or packet headers for address or
  protocol information
• Classification
• Identify packet against a criteria (filtering /
  forwarding decision, QoS, accounting, etc.)
• Data Transformation
• Transformation of packet data between protocols
• Traffic Management
• Queuing, scheduling and policing packet data

Source Network Processor Tutorial in Micro 34 -
Mangione-Smith Memik
14
Network Processor Applications

• Routing table lookup
• Determine the next hop for incoming packets
• Packet Classification
• classify packets using header fields against a
  set of rules
• URL-based Switching
• Distribute HTTP requests based on URLs.
• Transcoding
• Encryption/Decryption, intrusion detection,
  firewall, access control checking,
  denial-of-service

15
IPv4 Routing
P
P
P
B
A
Router
C

• Routers determine next hop and forward packets

16
Trie-based Routing Table Lookup
rt_ptr
trie_ptr
0
Trie block
Next hop 3
Next hop 4
15
Next hop 1
Next hop 2

• Trie block keeps pointers to route entry and
  other trie blocks
• Destination IP address bits are examined group by
  group (4-bit)

17
Example
rt_ptr
trie_ptr
0
Next hop 3
Next hop 4
15
Next hop 1
Next hop 2
Packet destination IP address 0x13fe2233
(0001,0011,1111,1110,)
18
IP Lookups using Multi-way Multi-column Search
Illustration of the idea with 6-bit
address Prefixes 1 101 10101
1 0 0 0 0 0 1 0 1 0 0 0 1 0 1 0 1 0
101011 101110 111110
Binary search does not work with variable length
strings.

• end up far away from the matching prefix
• Multiple addresses that match to different
  prefix, end up in the same region

19
Multi-way multi-column search
20
Packet Classification

• Routers are required to distinguish packets for
• Flow identification
• Fair sharing of bandwidth
• QoS
• Security
• Accounting, billing
• etc
• Packets are classified by rules
• Src IP, Dest IP, src port , dest port etc
• Classification Algorithm Metrics
• Search speed
• Storage cost
• Scalability
• Updates
• Etc.

21
Classification Hierarchical tries
Pankaj Gupta and Nick McKeown,"Algorithms for
Packet Classification", IEEE Network Special
Issue, March/April 2001, vol. 15, no. 2, pp
24-32.

• Extension of the one dimensional radix trie
• Construct trie recursively
• Contruct F1-trie on the set of prefix Rj1
• For each prefix p in F1-trie, we recursively
  construct (d-1) dimensional hierarchical trie on
  rules where RjRj1p

22
Classification Bitmap-intersection
The set of rules S that a packet matches is the
intersection of d sets, Si Where Si is the set of
rules that match the packet in the i-th dimension
alone.
0
0
Pankaj Gupta and Nick McKeown,"Algorithms for
Packet Classification", IEEE Network Special
Issue, March/April 2001, vol. 15, no. 2, pp
24-32.
23
URL-based switching
www.yahoo.com
Internet
Image Server
APP. DATA
TCP
IP
Application Server
Switch
GET /cgi-bin/form HTTP/1.1 Host www.yahoo.com

• Increase efficiency
• Tasks
• Traverse the packet data (request) for each
  arriving packet and classify it
• Contains .jpg -gt to image server
• Contains cgi-bin/ -gt to application server

HTML Server
Source Network Processor Tutorial in Micro 34 -
Mangione-Smith Memik
24
Transcoders

• Two important requirements
• If the receiver is not capable of interpreting
  the stored data (multimedia transcoders)
• wireless receivers, hand-held devices, etc.
• Compression for bandwidth and storage efficiency

Source Network Processor Tutorial in Micro 34 -
Mangione-Smith Memik
25
Summary

• NP is developing very fast and is a hot research
  area
• Multithreaded NP Architectures provide tremendous
  packet processing capability
• NP can be applied in various network layers and
  applications
• Traditional apps forwarding, classification
• Advanced apps transcoding, URL-based switching,
  security etc.
• New apps

26
Reference

• Pankaj Gupta and Nick McKeown,"Algorithms for
  Packet Classification", IEEE Network Special
  Issue, March/April 2001, vol. 15, no. 2, pp
  24-32.
• Bill Mangione-Smith, Gokhan Memik, Network
  Processing Applications, Architectures and
  Examples Tutorial at Micro 34, Dec. 2001
• B. Lampson, V. Srinivasan and G. Varghese, IP
  Lookups using Multiway and Multicolumn Search,
  IEEE/ACM Transactions on Networking, August 1,
  1997
• Intel IXP1200 Network Processor Family -
  Development Tools User's Guide, Intel