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2. Hardware Questions

2.1 What are the CoralReef machine specs?

A CoralReef monitor is just a PC computer with network cards that can listen to a type of network connection. The specs provided here reflect what we know to work. The hardware you choose must also be compatible with the type of UNIX you wish to use for running CoralReef (at the moment, drivers for FATM and POINT monitor cards only work under FreeBSD, and drivers for DAG cards work under Linux). We are likely to be able to support questions regarding these specifications, but unless the question is very general, we will not be able to answer questions regarding PC hardware.

The machines which we use follow the following specs:

  1. 1 A high performance motherboard such as one of the Tyan Thunder series. It is now quite common to find high performance motherboards that support 2 CPUs. None of the components of CoralReef are directly multithreaded. However, since the performance bottlenecks are not directly CPU related multithreading is not an issue. Multiple processor motherboards can be useful in monitor boxes since the second CPU can cover operating system overhead and run analysis tools, while the primary CPU is dedicated to data collection.
  2. 1 400+MHz PII/III/IV or equivalent CPU(s).
  3. 1 Ethernet card (on-board on many Tyans and other motherboards) (Any FreeBSD compatible card will do)
  4. 1 6GB or larger hard drive. Practically speaking, some sort of Ultrawide SCSI drives are required for any link that is close to full utilization. An OC3 link at full utilization is 155 Mb/sec. Even removing overhead, it will outstrip the Ultra ATA-100 limit of 100Mb/sec. The current generation of Ultrawide SCSI is Ultra160 or 160Mb/sec. Due soon is Ultra320 or a SCSI interface capable of 320Mb/sec.
  5. 1 VGA AGP video card (any brand, as long as it can do console)
  6. 1 Case/power supply suitable for your production/monitoring environment. We use 19 inch Industrial Rack-mount Computer SERIES, Model No. 566i2.
  7. 1 Memory: We recommend at least 256MB. We find the error detection and correction features of ECC useful. As one would expect, performance will improve with more memory.
  8. 1 A hard disk controller consistent with your drives. Since SCSI is backward compatible, getting a control which supports the latest SCSI standards is a wise investment. CAIDA has had good success with Adaptec controllers.
  9. 1 The monitor machine will need all the standard computer compliment (keyboard, cables, etc.,) but a mouse will not be necessary unless you wish to run X-Windows applications at the console.

2.2 What are the specifications for the OCx interface card?

This is specific to the link which you would like to monitor. The cards supported by CoralReef are:

  1. 1 ForeRunner 200E, by Marconi (formerly Fore) - OC3 ATM (fatm driver for FreeBSD only.)
  2. 1 POINT, by Applied Telecom - single-mode OC3 and OC12 ATM ("point" driver for FreeBSD only.) Unfortunately, Apptel has acquired by Conexant and renamed Mindspeed. Mindspeed has discontinued production of the POINT products.
  3. 1 DAG, by the WAND group at the University of Waikato - OC3 and OC12, ATM and POS (DAG driver for LINUX only)

2.3 What sort of splitters are required and where they be purchased?

It is essential that you get a splitter which matches the link that you are tapping. It is possible to use a multi-mode splitter on a single-mode interface, but it introduces additional attenuation. The best combination is to match single-mode splitters with single-mode links and multi-mode splitters with multi-mode links. The ForeRunner card is multi-mode; the Apptel POINT cards are single-mode, but both kinds of cards should be able to work with both kinds of links.

CAIDA uses two kinds of splitters from ADC.

  1. 1 The specifications for single-mode are: wideband, 1x2, 10/90 ratio, 1310nm and 1550nm, small ruggedized package, 3mm diameter reinforced cable pigtail option, angled polish SC/APC connector option.
  2. 1 The specifications for multi-mode are: multimode, 1x2, 50/50 ratio, 850nm, small ruggedized package, 3mm diameter reinforced cable pigtail option, standard polish SC/PC connector option

You can feed a single-mode signal into a multi-mode receiver if the splitter is 80/20 or 90/10, not 50/50.

2.4 Are there any remaining sources for the former Apptel POINT cards?

Unfortunately, CAIDA is not aware of any source for the POINT card.

2.5 I followed your specs and bought all the parts. Now when my machine boots up I can see that two devices try to share the same IRQ. Is this ok?

IRQ conflicts pose the same problems for monitor boxes as they would for any PC - basically, the machine will not run reliably (if at all) until all conflicts are resolved. The PCI bus tends to get very cluttered and your various cards are conflicting. This is really a PC hardware problem and not a CoralReef issue. We can suggest clearing the PCI bus and reseting the BIOS. If this does not help try playing with the different PCI related settings in the BIOS. Turn off all unneeded ports which require IRQ (like USB, Parallel printer etc) and try again.

2.6 Is there a vendor or system integrator you people can recommend?

A CoralReef monitor is just a PC compatible machine. Because we purchase equipment from many vendors, we cannot recommend any one in particular. If you follow the hardware list it's just a question of putting the machine together, installing FreeBSD on it and the CoralReef package.


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