CMR to RMU Protocol
RMU-CMS connection prerequisite
In order to connect then to the CMS, the RMUs must comply to the CMS-RMU interface definition. RMU requirements The RMU must meet some requirements in order to be able to be connected to the CMS:
- Have to be reachable through internet
- Have to provide a SSH access allowing the “scp” command
- Have to generate the traffic in a compressed (using DEFLATE algorithm) upx files
- Have to generate a csv file with the current file id.
- Have to grant read permission on both the upx files and the csv file
The frequency of the data gathering by the CMS is CMS dependant; usually it’s more than once a day.
RMU file naming convention
The RMU must record data in the upx file format and compress each file with the DEFLATE compression algorithm (the default algorithm for gzip).
All the compressed files must be located in the folder “/cygdrive/c/RMUHMI/compressed”. In this folder all compressed upx files must have the name “RMU_$name$id.zip” where $name is the global file name defined for this RMU (cf Error! Reference source not found.) and id is the unique file identifier of this file. The unique file id is a 6 digits number (e.g. 000302) representing the order of generation (increasing over the time).
For example, the name of the file #1240 of the bruxelles RMU, which as defined its global file name as “BRU”, is : RMU_BRU001240.zip .
For retrieving the files, the CMS need to know the number of the next file generated. This number must present in a csv file which location is “/cygdrive/c/RMUHMI/traffic_recorder.csv”. This file use the separator ‘;’ and the key “Files Start Index” for representing the next file number.
For example if the next file to generate is the number 1245 the file traffic_recorder.csv must contain a line with: Files Start Index;1245.
This number is “the number of the next file to generate”. For example if “the number of the next file to generate” is 1245, it means that the RMU is currently generating the file #1244 and that the file #1243 generation is finished.
CMS Data Retrieving
The following sequence diagram represents how the CMS retrieve data on a RMU:
RMU specific information
Some information must be provided in order to interconnect successfully the CMS and the RMU:
- RMU SSH access information :
- IP address of the RMU
- Port used for the ssh access
- Login of the ssh account
- Password of the ssh account
- Compressed Upx global file name
For example :
- IP : 212.123.456.67
- Port : 22
- Login : upxFinder
- Password : mys3cretP@ssw0rd
- Global file name : MYRMU
Adjacent RMUs and coverage overlap
When two RMUs are positioned with an overlap in their coverage, some PDU will be detected in more than one RMU. This is called a ‘doubloon’. The CMS allows doubloons detection. In order to detect those doubloons an ANSP shall provide the list of all RMUs that potentially have coverage overlaps.