Using Ada95 to Build Software for a Gigabit Layer 7 IP Using Ada95 - - PowerPoint PPT Presentation
Using Ada95 to Build Software for a Gigabit Layer 7 IP Using Ada95 to Build Software for a Gigabit Layer 7 IP Networking Device: Adas No Big Deal Anymore Networking Device: Adas No Big Deal Anymore Mike Kamrad Mike Kamrad senior
Using Ada95 to Build Software for a Gigabit Layer 7 IP Using Ada95 to Build Software for a Gigabit Layer 7 IP Networking Device: Ada’s No Big Deal Anymore Networking Device: Ada’s No Big Deal Anymore
Mike Kamrad Mike Kamrad “senior” Software Engineer “senior” Software Engineer kamrad@TopLayer.com kamrad@TopLayer.com +1.508.870.1300x139 +1.508.870.1300x139 FAX +1.508.870.9797 FAX +1.508.870.9797 www.TopLayer.com www.TopLayer.com
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♦ ♦ A Really Bitchin’ Data
A Really Bitchin’ Data-
Comm Product
♦ ♦ Architecture
Architecture
♦ ♦ Ada Software Development Environment
Ada Software Development Environment
♦ ♦ Obstacles and Lessons Learned
Obstacles and Lessons Learned
♦ ♦ Restricted Usage RTOS
Restricted Usage RTOS
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♦ ♦ Founded January, 1997
Founded January, 1997
♦ ♦ 155+ Employees
155+ Employees
♦ ♦ Headquarters in Westboro, MA, USA
Headquarters in Westboro, MA, USA
♦ ♦ Strong executive management team
Strong executive management team
♦ ♦
Chipcom, Fore Systems, DEC, Wellfleet/Bay Networks Chipcom, Fore Systems, DEC, Wellfleet/Bay Networks
♦ ♦ World
World-
class engineering team
♦ ♦
DEC, Fore, Chipcom, 3Com, etc. DEC, Fore, Chipcom, 3Com, etc.
♦ ♦
Major experience in ASICs Major experience in ASICs and and switches switches
♦ ♦ Private Company
Private Company -
Raised over $30M in funding
♦ ♦ Shipping Products: AppSwitch 2500
Shipping Products: AppSwitch 2500 -
October ‘99; AppSwitch 3500 AppSwitch 3500 -
June ‘00
♦ ♦ Over 125 customers… and growing!
Over 125 customers… and growing!
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♦ ♦ The AppSwitch is a high performance L4
The AppSwitch is a high performance L4-
L7 device with a powerful set of flexible features, called with a powerful set of flexible features, called e e-
Application Control. .
♦ ♦ It provides flexible solutions to today’s IP
It provides flexible solutions to today’s IP networking challenges including congestion, networking challenges including congestion, accounting, monitoring, high accounting, monitoring, high-
availability, responsiveness, and responsiveness, and security security. .
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♦ ♦ A powerful set of flexible high
A powerful set of flexible high-
performance features...
♦ ♦
Security Augmentation Security Augmentation
– – Packet Filter Firewall with Packet Filter Firewall with Syslog Syslog Reporting Reporting – – Filters for Filters for DoS DoS attacks attacks – – Flow Mirroring for IDS Flow Mirroring for IDS
♦ ♦
Application Accounting/Monitoring Application Accounting/Monitoring
– – TopFlow TopFlow protocol protocol – – TopFlow TopFlow Data Collector Data Collector – – TopView Graphs TopView Graphs
♦ ♦
Application Traffic Management Application Traffic Management
– – Application QoS Application QoS – – Application Balancing Application Balancing – – Application Redirection Application Redirection
…built on a powerful policy …built on a powerful policy-
based management model which includes a unique Application Definition Library which includes a unique Application Definition Library
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♦ ♦ Prioritize
Prioritize
FTP..…
Priority 1 Priority 2 Priority 3 Priority 4 etc.
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♦ ♦ Graduated Priorities
Graduated Priorities
Priority 1 Priority 2 Priority 3 Priority 4 etc.
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♦ ♦ Bandwidth Guarantees
Bandwidth Guarantees
8 Mbps per flow
Xing Streamworks MS Stream
H.323
Priority 1 Priority 2 Priority 3 Priority 4 etc.
2Mbps 1 Mbps 384Kbps 1Mbps
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♦ ♦ Firewall
Firewall
set by application between zones
FastPath FastPath Process Process
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♦ ♦ TopFlow
TopFlow displays message flow displays message flow statistics statistics
sent by application and user + L3/L2 data
FastPath FastPath Process Process Background Engine
FTP..…
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AppSwitch 2500
console console
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AppSwitch 3500
console console
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♦ ♦ “
“Touch Touch every every packet packet” ” switching engine switching engine
♦ ♦ Stateful packet inspection
Stateful packet inspection
♦ ♦ Datalink independent LAN/WAN switching
Datalink independent LAN/WAN switching
♦ ♦ Hierarchical Hybrid Queuing (HHQ)
Hierarchical Hybrid Queuing (HHQ)
♦ ♦ Customizable Application Policy Library
Customizable Application Policy Library
♦ ♦ “Automatic” operation
“Automatic” operation
♦ ♦ Scaleable, extensible architecture
Scaleable, extensible architecture
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♦ ♦ Key components
Key components
♦ ♦ TopFire
TopFireTM
TM Programmable
Programmable Silicon Switching Engine Silicon Switching Engine
– – Architected, designed, and patented Architected, designed, and patented – – Layer 7 at full wire speed at every port Layer 7 at full wire speed at every port – – Very scaleable and extensible Very scaleable and extensible – – Same architecture/software Same architecture/software in entire family in entire family
♦ ♦ TopPath
TopPathTM
TM Application Flow Switching
Application Flow Switching
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Packet Processing
Incoming Data Tx Queue Forwarding Tables
L2/L3
Priority Output Queues
Tx Queue Tx Queue
L4
Application Definition Library Application Policies
Application Control
Session Data
Stateful
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RE Chip QM Chip
TopFireTM chipset
MOM Chip MOM Chip
100 Mbps MII RAMbus DRAM QM SRAM SDRAM SRAM Lookup Tables Memory Fast Path Code, System Data, Memory Descriptors, Tables Memory Packet Memory Forwarding Engine Queue Manager MII Octal MAC 100 Mbps MII MII Octal MAC
AppSwitch 2500
RE Chip
Background Engine
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RE Chip QM Chip GMOM Chip
1000 Mbps RAMbus DRAM QM SRAM SDRAM SRAM Lookup Tables Memory Fast Path Code, System Data, Memory Descriptors, Tables Memory Packet Memory Forwarding Engine Queue Manager Dual Gig + 16 10/100 MAC
AppSwitch 3500
100 Mbps MII
RE Chip RE Chip
Background Engine Application Engine
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♦ ♦ Forwarding Engine
Forwarding Engine -
The main switching component to establish and maintain component to establish and maintain message flows, per network policies message flows, per network policies
♦ ♦ Background Engine
Background Engine -
The management control component that interfaces with the control component that interfaces with the network administrator network administrator
♦ ♦ Application Engine(s)
Application Engine(s) -
Protocol specific accelerator to handle complex protocols accelerator to handle complex protocols
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Forwarding Engine (FE) Architecture
♦ ♦ Custom
Custom RISC Core (ARC) RISC Core (ARC)
♦ ♦ Extensive Proprietary
Extensive Proprietary HW Assist HW Assist
♦ ♦ Tight Polling Loop
Tight Polling Loop -
NO INTERRUPTS
♦ ♦ Application “wrapper” and Slowpath coded
Application “wrapper” and Slowpath coded in in Ada Ada
♦ ♦ Fastpath and Application “policies”
Fastpath and Application “policies” handcrafted in handcrafted in assembly assembly
♦ ♦ Connection rates and throughput are
Connection rates and throughput are key key performance requirements performance requirements
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Background Engine Architecture
♦ ♦ Based on same ARC chip as FE
Based on same ARC chip as FE
♦ ♦ Event
Event-
driven system where events are:
♦ ♦ Arrival of message packets
Arrival of message packets
♦ ♦ Time expiration
Time expiration
♦ ♦ Multi
Multi-
tasking application to respond to various events events
♦ ♦ Division of application between
Division of application between
♦ ♦ Core modules
Core modules
♦ ♦ Extension modules
Extension modules
♦ ♦ Throughput and event processing are
Throughput and event processing are key key performance requirements performance requirements
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Background Engine Architecture
I procedural I/F procedural I/F procedural I/F procedural I/FProtocol Modules
procedural I/FSession Modules
procedural I/FProtocol Modules
dispatching on Interface
Core Extensions
Clock
DMA Input DMA Output
Packet/ Event Processor
Application/Service/Session Modules
Multi-Tasked "Continuous" "Timed" JobJar
Protocol or Session Modules
packets/events Qs "processed" packets QStrategic Disaster events
Disaster Manager
procedural I/FSingle Tasked
Worker Task Q Worker Task Worker Task Q Worker Task Q Worker Task Q Worker Task Q PO PO PO PO I H I I H IManagement Control DataBase
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Application Engine (FE) Architecture
♦ ♦ Based on same ARC chip as FE
Based on same ARC chip as FE
♦ ♦ Tight Polling Loop
Tight Polling Loop -
NO INTERRUPTS
♦ ♦ Basis infrastructure, written in C
Basis infrastructure, written in C
♦ ♦ Application specific software written in Ada
Application specific software written in Ada
♦ ♦ Throughput is
Throughput is key key performance performance requirements requirements
Ada Software Development Environment
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♦ ♦ Best combination
Best combination of language features for high
reliability and portability reliability and portability
♦ ♦ Strong typing
Strong typing
♦ ♦ OOP
OOP
♦ ♦ Multi
Multi-
tasking
♦ ♦ Exception handling
Exception handling
♦ ♦ Founder’s familiarity
Founder’s familiarity with Ada and frustration with with Ada and frustration with traditional languages traditional languages
♦ ♦ Implementation
Implementation based on GCC based on GCC, best chance for , best chance for ARC target ARC target
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♦ ♦ GNAT because GCC targeted ARC
GNAT because GCC targeted ARC
♦ ♦ Hosts:
Hosts:
♦ ♦ Solaris on SPARC
Solaris on SPARC
♦ ♦ Linux on PC
Linux on PC
♦ ♦ Targets:
Targets:
♦ ♦ Motorola MPC860 (PPC based) for WAN
Motorola MPC860 (PPC based) for WAN
♦ ♦ ARC
ARC
♦ ♦ Linux (for simulation)
Linux (for simulation)
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♦ ♦ Argonaut, British producer of computer
Argonaut, British producer of computer game technology game technology
♦ ♦ Provided as a
Provided as a “soft macro “soft macro” (in VHDL), ” (in VHDL), configurable to customer needs configurable to customer needs
♦ ♦ Basis for Forwarding Engine, Background
Basis for Forwarding Engine, Background Engine and Application Engines Engine and Application Engines
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♦ ♦ While a multiprocessor product, no
While a multiprocessor product, no distributed execution mode considered distributed execution mode considered
♦ ♦ Instead,
Instead,
♦ ♦ Forwarding Engine and Application Engines executes as
Forwarding Engine and Application Engines executes as single task single task, i.e. no RTOS , i.e. no RTOS
♦ ♦ Background Engine application executes with
Background Engine application executes with restricted restricted tasking operations tasking operations, per the , per the Ravenscar Profile Ravenscar Profile
♦ ♦ Control information is passed between Engines as special
Control information is passed between Engines as special IPC protocol IPC protocol
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♦ ♦
No task hierarchy No task hierarchy
♦ ♦
No dynamic creation of No dynamic creation of protected objects protected objects and tasks and tasks
♦ ♦
Tasks Tasks
♦ ♦
No entries No entries
♦ ♦
No abortion nor ATCs No abortion nor ATCs
♦ ♦
No select statements No select statements
♦ ♦
No user No user-
defined attributes
♦ ♦
No dynamic priorities No dynamic priorities
♦ ♦
No requeue No requeue
♦ ♦
No formal termination No formal termination ♦ ♦
Protected Objects Protected Objects
♦ ♦
Limited to one entry Limited to one entry
♦ ♦
Limited queues to one caller Limited queues to one caller
♦ ♦
No requeue No requeue
♦ ♦
Barrier conditions limited to single Boolean variable Barrier conditions limited to single Boolean variable ♦ ♦
Interrupt handlers defined through protected procedures Interrupt handlers defined through protected procedures
♦ ♦
Priority Priority-
based scheduling with time with time-
slicing within priorities
Obstacles and Lessons Learned
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Limitations on Ada Usage
♦ ♦ Not used
Not used
♦ ♦
Real types Real types
♦ ♦
Goto Goto
♦ ♦
Annexes E Annexes E-
H
♦ ♦
Functions returning unconstrained objects Functions returning unconstrained objects
♦ ♦
Predefined I/O Predefined I/O ♦ ♦ Limited use
Limited use
♦ ♦
Child generic units Child generic units
♦ ♦
Formal package parameters Formal package parameters
♦ ♦
Dynamic slices and aggregates Dynamic slices and aggregates
♦ ♦
Length attribute Length attribute
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♦ ♦ OOP
OOP -
Reinforced relationships relationships among “modules”, among “modules”, “interfaces” and “state block” “interfaces” and “state block”
♦ ♦ Root_Storage_Pool type
Root_Storage_Pool type -
Supports total total memory management memory management
♦ ♦ Controlled and Limited_Controlled types
Controlled and Limited_Controlled types -
Get “closure” “closure” on
resource usage resource usage
♦ ♦ Interfacing to C
Interfacing to C -
Because there’s lots lots of legacy and third
party software software
♦ ♦ Various Interfaces to hardware
Various Interfaces to hardware
♦ ♦ GNAT’s pragma
GNAT’s pragma Assert Assert
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♦ ♦ Learning Curve
Learning Curve
♦ ♦ Intensive internal training and advocacy
Intensive internal training and advocacy
♦ ♦ Incomplete Tool Chain for ARC
Incomplete Tool Chain for ARC
♦ ♦ GCC consultants to bridge the gap
GCC consultants to bridge the gap
♦ ♦ Inadequate RTOS
Inadequate RTOS -
GNAT RTS and RTEMS too excessive and non too excessive and non-
unified for ARC
♦ ♦ Internal development of lightweight RTOS
Internal development of lightweight RTOS
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♦ ♦ Guidelines to guide user through “choices”
Guidelines to guide user through “choices”
♦ ♦ Budget resources for tool support
Budget resources for tool support
♦ ♦ Tool chains reflect their legacy
Tool chains reflect their legacy
♦ ♦ Be supportive to new user through the “niggling”
Be supportive to new user through the “niggling” period period
♦ ♦ Watch out for generic foot print
Watch out for generic foot print
♦ ♦ Pay attention to exception handling costs
Pay attention to exception handling costs
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♦ ♦ Built to work with
Built to work with GNAT GNAT
♦ ♦ Simplify the functionality of RTOS to only
Simplify the functionality of RTOS to only support support Ravenscar Ravenscar-
like profile
♦ ♦ Reduce the
Reduce the “thickness” “thickness” of layers in GNAT
RTOS RTOS
♦ ♦ Simply the “kernel” for
Simply the “kernel” for bare machine bare machine execution execution
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Ada application Ada-specific runtime routines RT POSIX compatible Kernel
C application
OS binding to Kernel
RT-POSIX binding to Kernel
Kernel binding to processor
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Ada application Ada-specific runtime routines
C application
RT POSIX compatible Kernel Kernel binding to processor