The Candela Technologies
LANforge platform excels at several different aspects of Network-related testing and simulation.
The LANforge-FIRE configuration, used for Traffic Generation, simulates the edge of the
network you are testing. The LANforge-ICE feature set, used to simulate the core of a
network, tests and verifies applications that communicate through the core. LANforge-ICE
can replace or augment any requirement for T1, DSL, OC3, OC12, Satellite, Dial-Up and other
limited speed or lossy network link in your network diagrams. LANforge-FIRE and
LANforge-ICE are two personalities of the same software, so they can be configured to run
simultaneously on the same set of hardware.
www.candelatech.com | sales@candelatech.com | +1 360 380 1618
The LANforge-FIRE platform can generate FTP, HTTP, HTTPS, VoIP (SIP, H.323, RTP, RTCP), TCP/IP, UDP/IP, Ethernet, PPPoE, PPP-over-T1, and custom payloads. It currently supports Ethernet (up to Gigabit), 802.1Q VLAN, PPP-over-T1, and Token Ring networks. LANforge software includes support for testing file systems, including network file systems like NFS, SMB, and iSCSI. LANforge-FIRE can be configured in many different ways, offering Gigabit Ethernet support on the high end, and high-density and inexpensive 10/100 Ethernet ports for lower speed applications. The MAC-VLAN feature allows you to emulate an entire subnet of machines with a single LANforge machine. It is specifically designed to meet the requirements of testing today's Last-Mile and Metro-Edge systems which must handle simultaneous customer traffic across a large number of ports, equipment including Digital Subscriber Access Multiplexers (DSLAMs), Cable Access Systems, and their respective Customer Premise Equipment like DSL and Cable modems. LANforge is a capable tool for testing higher-speed networks up to Gigabit line speeds.
LANforge-FIRE can also be an excellent choice for stress testing your own Linux hardware, especially server type configurations that rely heavily on real-world networking performance. For example, if you are trying to get an idea of how well your new dual-CPU system with 2 Gigabit NICs performs, you could load LANforge on each one (with your own custom compiled kernel if you wish), and drive Ethernet, UDP, TCP, FTP and other traffic against other LANforge enabled stations.
The affordable cost per port, ease of use, and standards compliant networking
stack makes the LANforge an essential piece of equipment in every test lab.
The LANforge system consists of a single manager process, and one or more traffic generator machines (clients/cards). The cards are connected to the manager over an ethernet management interface so that all management traffic is out-of-band, which ensures accurate reports regardless of the state of the network under test. Only the data-producing ports should be connected to the device or devices under test.
The LANforge Manager runs the management server, and potentially, the LANforge-GUI (graphical user interface). Because the LANforge-GUI connects to the manager over TCP/IP, it can be run remotely, and because it is written in Java, it will work on many different types of computers, including Windows, Solaris, and Linux. Depending on your hardware and speed requirements, you can also run the GUI, Management Server, and traffic-generation server on a single Linux system. That allows the minimum LANforge-FIRE installation to be a single machine with 2 or more ethernet interfaces.
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
In order to have a fully functional LANforge-FIRE testing system, you will need at least
one of the Data Generator units with at least two
ethernet ports. From this basic configuration, you can add more data generators and more
ports to each data generator. If you do not have Candela's Linux kernel patches
installed, the minimal configuration is two machines with at least one port each.
www.candelatech.com | sales@candelatech.com | +1 360 380 1618
Suppose that you have a DSLAM you wish to test with the LANforge package. The DSLAM has one 10/100 BaseT ethernet interface that goes towards the network, and supports ninety-six (96) CPE DSL modems. Each DSL modem has at least one ethernet port for the customer's equipment (or LANforge) to connect to.
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
LANforge can also test Data-over-Cable systems. The example below illustrates how you might set up LANforge to test a system that includes a router for the upstream data traffic.
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
LANforge supports Linux kernel accelerated UDP traffic generation and reception. This feature, known as LANforge-Armageddon, generates line-speed packet rates on 10/100Mbps networks, and can currently generate up to 999Mbps on Gigabit Ethernet networks.
LANforge-Armageddon can also customize or randomize various Ethernet, IP, and UDP
header fields, making it an excellent tool for break-it testing to see if your
system-under-test can withstand the onslaught.
www.candelatech.com | sales@candelatech.com | +1 360 380 1618
LANforge directly supports: Ethernet, PPPoE, UDP/IP, TCP/IP, FTP, PING, GOPHER, VoIP (SIP, H.323, RTP, RTCP), HTTP and HTTPS. Generally, these protocols will be sufficient to test any network. Some users may want to specify their own packets for specific tests, and to that end, LANforge gives you the ability to input any ethernet packet directly onto the network. The LANforge-GUI also offers some protocol builders for common protocols like TCP/IP, UDP/IP, and Ethernet.
The World Wide Web generally uses the HTTP protocol, which runs on top of TCP/IP. Typical traffic is highly bursty and contains random sized packets. It is also largely unidirectional, with the bulk of the traffic flowing downstream towards the customer. Because TCP/IP is a stream based protocol, if you are testing a device that routes (as opposed to a simple layer-two bridge) then you will most likely want to have many relatively slow connections flowing from a few LANforge ports representing servers to many LANforge ports representing the clients. These Cross-Connects should have bursty traffic rates, as well as random payload sizes.
You can set up a web server (potentially on another LANforge machine) and tell LANforge to download URLs at some specified rate (URLs-per-10-minutes). Unlike browser tests, LANforge will not try to cache any values, so you will always get the traffic patterns you request!
Most other, non-streaming, protocols also run over TCP/IP. It has the nice feature of using all available bandwidth, but it also slows down when the network becomes congested. If you are trying to gauge the total throughput of a system, TCP/IP Cross-Connects with large (4000 bytes or higher) payloads will be the easiest method. Just tell the LANforge to run at a speed higher than your system-under-test can handle, and then watch the actual rate that LANforge displays.
Another popular Internet protocol is FTP. FTP generates highly unidirectional traffic in either the upload or download direction. LANforge-FIRE supports FTP uploads as well as downloads. LANforge machines also come with an FTP server, so you will not need any external equipment to do your testing, though you may use your own FTP server if you so wish.
LANforge-FIRE can be used to generate file-system traffic (i.e., read and write to files on the local machine). You can specify, among other features, the size and number of files to read/write and the size of the individual calls to the read and write system calls. You can also calculate and check a 32-bit checksum on the reads & writes for correctness checking. Because Linux can mount file systems over the network, including NFS, SAMBA (SMB), and iSCSI, this feature can allow you to generate network file protocols as well.
LANforge-FIRE can launch and display results from almost any command-line Linux tool, such as ping and traceroute. LANforge facilitates your testing by providing a framework in which to run such tools and store their results in a centralized place. Contact Candela Technologies if you have questions about a specific program.
Voice Over IP (VoIP) and other streaming media protocols usually run over UDP/IP. This is a connectionless protocol, and it may lose or re-order packets from time to time. However, it has much less overhead than TCP/IP, and because most streaming protocols are real-time sensitive, it is better to be fast and occasionally lose a packet, than to always run slow(er).
LANforge supports the SIP and H.323 VoIP messaging protocols and can generate the RTP media stream as well. A male and female voice wav file is included and the customer can provide other wav files as well. Several RTP codecs are supported including G711u, G729, G726-16, G726-32 and Speex. More codecs will be supported as customers request them. A high-end LANforge chassis can emulate 140 or more VoIP phones, including all SIP messaging and RTP media streams. Multiple LANforge machines can be clustered together for even more call capacity.
The Trivial File Transfer Protocol (TFTP) and Boot Protocol (BOOTP)/Dynamic Host Control Protocol (DHCP) are often used to boot network computers and Customer-Premise-Equipment (cable/DSL modems). All three protocols run over UDP/IP. Generally, these protocols run as fast as their network will allow, so if you are trying to simulate this protocol you will want to tell LANforge to run at the highest speed possible without dropping more than 1% of the traffic. These Cross-Connects should be of type UDP/IP and the payload size should fit into the MTU for your network.
The LANforge-ICE platform is used to simulate T1, DS3, OC-3, OC-12, GigE, DSL, Satellite, Dial-Up, and other Wide Area Networks (WANs). LANforge-ICE can simulate many attributes of a WAN, including latency, jitter, packet-loss, packet-reordering, packet-duplication and bandwidth constraints. Latency and jitter is configurable in 1ms increments, and the packet-loss, reordering, and duplication settings are X packets per million.
LANforge-ICE can be configured to run entirely on a single laptop provided
by Candela Technologies or a distributor, and it can also be configured on rack-mounted
units or your own machines. The Linux version is currently more accurate and faster,
but the Windows solution is fine for speeds of 45Mbps and slower.
LANforge-ICE is usually installed on a single machine with two Ethernet ports free for use by LANforge. It takes exactly two ports to simulate a WAN link, but if you wish to run several WAN simulations simultaneously, you may order a LANforge-ICE configuration with 4 or more ports. LANforge-ICE also supports 802.1Q VLANs, and when used in conjunction with a properly configured VLAN ethernet switch, a single LANforge machine can easily emulate 48 or more unique networks configurations. The devices under test do NOT need to use or support 802.1Q VLANs, just regular ethernet.
See the LANforge Standard Systems page for suggested configurations.
|
