LANforge Fire Traffic Generator - Testing Specific Protocols
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.
Generating World Wide Web (HTTP) Traffic
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.
Generating FTP Traffic
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.
Generating File-System Traffic
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.
Using LANforge to integrate generic programs
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.
Generating VoIP & RTP traffic
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.