“Real Life” System Testing of Networking...

“Real Life” System Testing of Networking

EquipmentBill Eklow, Cisco Systems Inc.

Josh Goldstein, Ixia

The Pervasiveness of the Internet• Home access

– High speed connections– Home banking/stocks– Travel– Shopping– Google– IM

• Business– B2B– Web meetings/VOD– Application sharing– VoIP

The New, Critical Nature of Data

• 911 VoIP call

• Nasdaq Stock Transactions

• On-line banking

• Email

BranchOffice

LeasedLine

Main Office

BranchOffice

ExtranetPartner

AccessNetwork

Customers

Service ProviderNetwork

EdgeRouter

Core Router

CPERouter

LAN Router

The Function of Routers

Common Router Architecture

1. Routing protocol and data traffic is received via the physical ports (i.e. Ethernet, ATM)

PortPort

PortPort

SwitchingFabric

Typical RouterArchitecture

ControlPlane

Applications

1

2

3

4

1

2. Routing traffic is sent to the control plane and stored in the Routing Information Base (RIB)

3. Based on routing algorithms, the best route is populated in the Forwarding Information Base (FIB)

4. Applications are router specific – QoS, LSPs, multicast, filtering, load balancing

• Hardware vs Software implementation• Efficiency of routing algorithms• Switch fabric packet performance

Plethora of Routing Protocols

MP-BGP (RFC 3107)

LDP

IS-ISv6

RSVP-TEMPLS Signaling

BGP+

OSPFv3

IPv6

IPv4

Category

RIPng

BGP

IS-IS

OSPF

RIP

Protocol

Layer 2 VPNMPLS VPN

BGP Layer 3 VPN (RFC2547bis)

Inter-AS VPN

VPLS

PIM-SMv6

MLDv1

MLDv2

PIM-SM

IGMPv3

IGMPv2

IGMPv1Multicast

Category Protocol

4 Elements of a Router

Key Metrics for Router Performance

• Throughput/latency/consistency

• Data integrity

• Routing capabilities/protocols

• Services (Security, QoS)

Challenging Areas In Router Testing

• Keeping up with new technologies and developments

• Scaling the test environment

• Emulating realistic traffic scenarios

• Simplifying the test process

Some State of the Art Test Areas

• Test requirements induced by real-time IP traffic– Videos should arrive smoothly, not choppy– Voice services need to work all the time, with quality

comparable to public telephone network

• New applications are based on router services– High availability, routing convergence– Multicast transport, IPv6 support

Trend: Testing Routed Services

• Verify end-to-end VPN mapping over a routed core backbone network

• Both Layer 2 (ATM, Ethernet, Frame Relay) and Layer 3 VPNs increasingly becoming integrated into routers

• Complexity: Many different hierarchies of protocols, plus different IP address realms in a single test

Trend: Testing Special Devices

• Routers are no longer just IP forwarding boxes

• Firewalls, content and general application switching, soft (telephony) switching and other functions become more and more integrated in routers

• Application layer functions within the router need to be tested with tailored emulators

Single vs. Multiple Device Tests

• Single device configurationtests the routing engineand the switching fabric

• Multiple device configuration adds ports and protocols to stress the device, and to do convergence testing

TestPort 1

TestPort 2Device

Under Test

SystemUnder Test

TestPort 1

Test Port 3

TestPort 2

Data Plane Testing Objectives

• Validate the router forwards traffic to the correct interface

• Measure data plane performance– Latency– Throughput– Data Integrity– Jitter– Sequence of packets

• Test advanced features such as non-stop forwarding

Data Plane Testing Setup

Emulated Routers Send Traffic to Advertised Routes

Measure Throughput

Measure Latency

Data Plane Test – Sequence Checking

Real-time StatisticsSmall Errors

3

BigErrors

Reverse Errors

Total Errors

1 2

Transmit Sequence

1 2 3 4 5 6 7 8 9 10

1 3 2 4 5 8 6 7 9 10

Reverse Error Big Error Small Error

Error Threshold = 2

6

Track sequence validity for up to 128,000 flowsPerform sequence checking while getting first/last latency values per flow

Data Plane Test – Data IntegrityInto Router:

TTL = 64Checksum = 0x829F

Out of Router:

TTL = 63Checksum = 839F

Data Plane Test – Data Integrity

Problem: What if a router bug causes a packet payload change?

• Since the checksum is recalculated, the packet will look valid, but the user’s data is corrupt.

Solution: Test equipment adds second checksum, only calculated on packet payload

• Now, corrupt user data can be identified.

Control Plane Testing Objectives

• Validate the router correctly populates its RIB and FIB

• Find the maximum number of routes the router can handle

• Find the maximum number of routers the router can talk to

• Measure response time to network topology changes

Route Capacity Test Setup

NetworkA

I know how to reach Network A.

I know how to reach Network B.

Please send this traffic to Network XYZ.

RouterUnderTest

I know how to reach Network XYZ.

NetworkB

NetworkXYZ

?

Routing Convergence Test Setup

NetworkA

I know how to reach Network A.My cost to reach Network A is 10


My cost to reach Network A is 50

Please send this traffic to Network A.

RouterUnderTest

Routing Convergence Test Setup

NetworkA


My cost to reach Network A is 50

Please send this traffic to Network A.

RouterUnderTest

I know how to reach Network A.My cost to reach Network A is 75

Test Equipment Hardware Architecture

1. High port density2. Layer 2-3 wire-speed data

plane testing features3. High scalability and

performance for routing protocol emulations

4. Supports Layer 4-7 statefultransactions; “Real World Traffic”

5. Enables porting of 3rd party applications to Ixia platform

6. System scalability to several hundred ports

1

3 45

CPU per port

2 Dedicated FPGA logic per port

Advanced Router Testing – IPSEC

IxChariot:Layer 4 Traffic

IPSEC tunnels

• Test router services such as IPSEC VPNs• Performance, scalability, real world traffic

Routing System Test• Connect multiple devices and benchmark

performance as a system or network• Routing Protocol Performance & Conformance• Validate Wire-Speed Traffic, QoS, Sequence

Checking, Throughput, Latency, Packet Loss• Use Real World Traffic to emulate deployed

network

• Connect multiple devices and benchmark performance as a system or network

• Routing Protocol Performance & Conformance• Validate Wire-Speed Traffic, QoS, Sequence

Checking, Throughput, Latency, Packet Loss• Use Real World Traffic to emulate deployed

network

©2004 Ixia. All rights reserved.

IxChariot – Customer Market Acceptance

Market Facts

IxChariot and its predecessor, Chariot have been successfully used by thousands of enterprises, network service providers and equipment manufacturers for more than 6 years:

Enterprise Customers:

Carriers/MSOs:

Network Equipment Manufacturers:

Silicon Chip Developers:


IxChariot – How it works

IxChariot reproduces this conversation in rhythm using the same:

Transport layer protocol

Packet sizes and quantities

Packet headers

IxChariot can reproduce scalable amounts of enterprise application transactions –maintaining the same rhythm.

IxChariot does not need to talk to real application servers.

IxChariot does not deviate from its scripts.


Application Testing – Stateful Transport Layer Sessions

Emulate traffic patterns of multiple applications

Use full TCP stack

Measure “goodput” available to the application layer


IxChariot – Principal Application AreasTest the performance of a device to handle mixed mode, multi-protocol application traffic.

Determine the ability of WAN links to cope with additional

traffic introduced by new applications.

Test the ability of a system to handle network congestion caused by application traffic. Measure the impact of traffic prioritization.


IxChariot Hardware Platforms – ALM1000T8

PowerPC 750FX per port

Up to 1GB of RAM per port

1. Eight port 10/100/1000 Ethernet Load Module

2. RJ-45 Copper interfaces

3. Layer 4-7 capability

Use whenOnly Layer 4-7 testing is neededPerformance needs are medium to high ALM1000T8 – IxChariot,

WebLOAD, IxLoad, IxVPN


IxChariot Hardware Platforms – PCs, etc.

Combine Ixia Hardware with other platforms whenExisting infrastructure is entrenched (experience, ROI, relationships)Test plans rely on specific devices (e.g., WLAN PDA testing)Remote labs cannot cost justify Ixia hardware

Conclusions

• Testing a modern router is a complex endeavor

• Test equipment technology has matured in both hardware and software

• Careful test planning at multiple product development stages reduces time-to-market and increases quality

“Real Life” System Testing of Networking...

Documents

Transcript of “Real Life” System Testing of Networking...