Accessing Data on Your Test Box
This page very briefly describes how you can access the data taken with the test box at your site. The data formats are still preliminary and may chance without notice.
There are two ways to access the data:
- By listening to a port on the machine.
This method gives you access to the delay and routing information within seconds after it has been take. However, as we explained in the TTM RIPE Document, an individual test-box only has access to the results of the incoming delay measurements and the outgoing routing vector determinations.
- By copying the data-files generated on your machine.
This method will give you access the results of both incoming and outgoing measurements. However, the data first has to be collected at a central point and processed, so there will be a delay before the data is available.
The local data port
Before you can access the data, your machine(s) has to be added to a local configuration file. There is no official procedure for this (yet), for the time being, simply email us the IP address (range) of your machine(s).
A server will be started as soon as the machine starts data-taking. To listen to the server, type:
telnet test-box 9142
where test-box is the name or IP-number of your test-box.
If the test-box is taking data, then you will see something like this appear on your screen, updated about once a second:
|RCDP 10 2 18.104.22.168 1197 22.214.171.124 6000 892652515.866538 0.009550 0X107 0X107 892652515
RCDP 10 2 126.96.36.199 2185 188.8.131.52 6000 892652526.730175 0.000265 0X107 0X107 892652526
SNDP 9 892652524 -h tt06.ripe.net -p 6000 -n 100 -s 892652524
RCDP 10 2 184.108.40.206 2189 220.127.116.11 6000 892652539.938796 0.000286 0X107 0X107 892652539
RVEC 13 18.104.22.168 22.214.171.124 892733035 9 126.96.36.199 188.8.131.52 184.108.40.206 220.127.116.11 18.104.22.168 22.214.171.124 126.96.36.199 188.8.131.52 184.108.40.206
... 50966 44933.180 127.127.20.0 $GPGGA,121709.00,5222.4269,N,00453.3363,E,0,03,,222.1,M,46.7,M,,*43
50966 44934.120 127.127.20.0 $GPGSA,A,1,,03,,,21,,,31,,,,,,,*1C
50966 44934.260 127.127.20.0 $GPGSV,2,1,05,03,78,135,19,21,57,125,20,22,17,179,,23,44,065,*72
50966 44934.340 127.127.20.0 $GPGSV,2,2,05,31,55,292,10,,,,,,,,,,,,*46
50966 44934.420 127.127.20.0 $GPZDA,122854.00,02,06,1998,00,00*63
Lines can either start with a 4-letter identifier followed by one or more numbers and a carriage return to terminate it, or by 2 numbers, a fixed IP address (127.127.20.0) and a string. The formats are explained here for the lines starting with a 4 letter identifier and here for the other strings. Data will appear on your screen until you type control-].
If the test-box isn't taking data, then you will see something like:
telnet: Unable to connect to remote host: Connection refused
Interpreting the strings
Lines starting with a four-letter keyword are generated by one of the data-taking processes on the machine. The keyword is followed by an integer indication the number of fields that will follow and 0 or more data fields. Fields are separated by spaces. A new line will be written whenever a data collection process produces output. Currently three keywords have been defined:
- SNDP (SeND Packet), nine data-fields:
- Time that the packet was sent (seconds since Jan 1, 1970 using the Unix time conventions).
- -h (fixed, will disappear soon)
- Destination of the packet.
- -p (fixed, will disappear soon)
- Port number on destination machine.
- -n (fixed, will disappear soon)
- Message length in bytes.
- -s (fixed, will disappear soon)
- Sequence number of the packet.
- RCDP (ReCeiveD Packet), 12 data-fields:
- Version number of output format (1 or 2)
- IP address of the host that sent the packet.
- Port of the host that sent the packet.
- IP address of the host that received the packet.
- Port of the host that received the packet.
- Arrival time (seconds since Jan 1, 1970) at the receiving machine.
- Delay, time needed by the packet to travel from source to destination (seconds).
- NTP status bits of sending host, should be 0x107 for a valid measurement.
- NTP status bits of receiving host, should be 0x107 for a valid measurement.
- Sequence number of the packet. (Version 2 only).
- NTP error estimate for the clock on the sending machine.
- NTP error estimate for the clock on the receiving machine.
- RVEC (Routing VECtor), variable number of data-fields:
- Start point of vector (IP address).
- End point.
- Time that the vector was determined.
- Number of intermediate points.
- IP address of first intermediate point.
- IP address of second intermediate point.
Please note that this is a preliminary format and that fields may be dropped or added on short notice.
Interpreting the GPS Strings
Lines starting with two numbers and an IP-address (usually 127.127.20.0 or 127.127.31.0) are produced by the GPS receiver. They give the current status of the GPS receiver and are produced about once every 64 seconds. The format depends on the type of receiver that you have:
- Motorola Oncore-VP. These are receivers with a small black antenna and a coax cable to the test-box.
- Trimble Palissade. These are receivers with a large white antenna.
- The receiver needs time to respond to a change in the antenna position, from approximately 1 minute if it is moved by half a meter to approximately 30 minutes if it gets a complete new view of the sky.
- This information is only available after we have switched on the Test Traffic software. We can only do this after the machine is on the net.