![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
|||||||
|
||||||||||||
|
||||||||||||
![]() |
||||||||||||
Site PlanningThis section contains all inormation that is necessary to plan and prepare the installation of a test-box. First we describe planning considerations for the test-box itself, then for the GPS antenna and the cabling between the two; finally there is a section about the contact information we need as well as aspects of test-box operations. This material applies to test boxes of series ‘C’ starting with serial number 48 (tt48). For earlier test boxes see RIPE-168, Installing and Hosting a Test-Box. The Test-Box. We are currently investigating “thinner” 1U or 2U versions of the test-box chassis, but they are not available yet. We are also investigating 48V DC power options. If you need this, please let us know as early as possible. The network connection of the test-box is vanilla 10baseT or 100baseT Ethernet. Since the box does not listen to traffic which is not addressed to it, it is possible and recommended to put it on a switch or an Ethernet segment with no other critical hosts. As the box is to take inter provider measurements it should be topologically close to your border router(s) in order to exclude effects of your own topology from the measurements. We prefer the box to be on the outside of any firewall in order to prevent firewall configuration problems. If firewalls cannot be avoided the following connectivity needs to be available:
You will need to assign an IP address to the test-box and also provide us with the netmask of the network. We also need the address of a router we can use as a default router from the test-box. The box can also use RIP or IRDP to determine this. If there is a local DNS resolving name server, we would like its address too. The test-boxes are delivered pre-configured. Installation just requires installing them in their rack, applying power and checking whether the user-interface is reachable. GPS AntennaThe GPS antenna is a Trimble Acutime 2000. This is a self contained GPS receiver with antenna for outdoor mounting. In order to receive the GPS satellite signals the antenna needs to be mounted in a
place with a clear ‘view’ of as much of the sky as possible. Contrary to other satellite equipment the antenna does not need to be pointed in a specific direction; rather the amount of sky visible to it will
determine reception quality: the more of the sky you can see from an antenna site, the better. The signals will be blocked by almost all solid materials. The antenna can be mounted behind glass which
is neither metal-coated nor very thick. The best antenna location is on the roof of a building witha good view of the sky overhead. The second best is on an outside wall with as much distance as possible from other buildings or obstructions. The best places for wall mounting are those which have a good view straight up which is not obscured by overhangs such as roofs and balconies. Also the corner of a building is generally preferable to the center of a long wall, because of the larger angle of view that a corner position provides. As a last resort, one can put the antenna inside a non-coated window with a good view; however this often provides only marginal reception conditions with long initialisation times for the receiver. Conditions at windows can often be drastically improved by mounting the antenna just outside the window where it has a better view straight up. Look on the GPS Examples page for photographs of some typical sites and the GPS reception conditions measured there, The antenna is connected to the test-box by standard CAT-5 twisted pair wiring which is present in many modern office buildings. The connection can be patched via patch panels using standard ‘straight’ patch cables which are used for Ethernet patches. It is important to be sure that the building wiring really provides all 4 pairs (8 wires) required by the CAT-5 specification. We have come across wiring only providing two pairs, because that is sufficient for many applications. Power is supplied to the antenna from the test-box, so no other connections are needed. The hardware is tested with 300m of CAT-5 cable between the test-box and the antenna prior to shipment. We deliver this unit with 6m of outside grade cable. This cable is terminated with an RJ-45 plug that can be connected to your building wiring or directly to the test-box. Normally there is a set of DB-25 connectors near the end of it for conversion to the RJ-45. The antenna-end of the cable is terminated with a circular plug of ~2cm diameter (Deutsch #26C-221S1), facilitating threading the cable through holes in building walls and tight conduits. For shorter cable runs we expect that it is possible to use twisted pair cabling that does not conform to the CAT-5 standard. If you already have such cabling installed in a suitabe place, you may consider using it instead of installing new CAT-5 cabling. In particular we expect that normal telephone wire will work for a few 10s of meteres. Contact us to evaluate your particular situation.
Connecting any other equipment here may result in damage to that equipment. You will have to observe local electrical as well as lightning-protection codes and regulations. Buildings with CAT-V wiring provide quite some flexibility in panning your antenna location because you can patch the connection to a potentially big number of places. If you need to decide between a number of possible locations this enables you to try them out, monitoring the reception conditions through the test-box user interface. In case you have a really difficult suituation and it is hard to find a suitable antenna location, we can provide a site survey tool. This hand held tool shows GPS reception conditions and can log them over a longer period in order to evaluate possible antenna locations. Please contact us at tt-ops@ripe.net for more details. Once the antenna location is fixed, please provide a reasonable estimate of the total length of the connection between the antenna and the test-box for calibration purposes. While this is not essential, it will increase the accuracy of the measurements. Trimble makes a lighnting protection product. If this is suitable for your situation you can order these directly from Trimble. Please let us know if you are using this as we may offer this as an option if demand is high enough. Contacts & OperationsThe test-boxes are operated remotely by the TTM operations center at the RIPE NCC. After installation there is no local support needed for normal operations. However we ask you to provide contact information in case we need local support to resolve unforeseen problems. We would like to have contact information for three different roles: measurements, operations and billing. Of course one person or group can serve multiple roles depending of your organisation. The operations contact has physical access to the test-box and can power-cycle it on request. They also have knowledge about the network connectivity of the test-box and can isolate and fix problems related to that. In case of major upgrades to the test-box software the operations contact may be requested to power down the test-box, exchange two disk trays and reboot. Unless there are local problems with network connectivity, we expect to need such assistance at most every three months. The billing contact will receive all invoices and all payment related correspondence. The measurement contact coordinates the use of TTM within your organisation. They are contacted about changes in the presentation of the results or when new products based on the measurements become available. They will also be informed about general developments of TTM. OrderingTo order a test-box, please fill out the order form at http://www.ripe.net/ripencc/mem-services/ttm/Host_testbox/host_testbox.html, and send it in.
|
||||||||||||
![]() |