GPS NMEA streaming over UDP

[Dan Frey]

This ISR sample application  uses a tclsh script managed by an EEM applet to stream NMEA formatted location data in UDP packets (with configurable port number) to a defined target.  TCLSH script is in the attached zip file and also requires the following CLI commands.

! CLI commands required:

event manager environment server "your server ip address"
event manager environment udp_port "your udp port"

event manager applet NMEA
event syslog pattern "LINEPROTO-5-UPDOWN: Line protocol on Interface Cellular[0-9\/]+, changed state to up" maxrun 31536000
action 010 cli command "enable"
action 020 syslog msg "NMEA streaming starting now"
action 030 cli command "tclsh flash:stream_NMEA2.tcl $server $udp_port"

aaa new-model
 aaa authentication login nologin none
 aaa authorization exec nologin none
controller Cellular <number>
  lte gps mode standalone
 "lte gps nmea ip" for 819.  "lte gps nmea" for all other platforms

[manningnavcomp]

How can this be modified to only send the GPS every 2 minutes?  Also, can the GPS be configured to send only the GPRMC message?

[Dan Frey]

Replace the stream_NMEA2.tcl with this code and it will send $GPRMC every 2 minutes.  

package require udp

set server [lindex $argv 0]

set sudp_port [lindex $argv 1]

puts "server and port = $server $sudp_port"

set intf [ios_config "int loopback 7" "description DO NOT REMOVE" "ip add 1.2.3.4 255.255.255.255"]

set pt [exec show line | inc NM]

regexp {.?\s+(\d+)\s+TTY} $pt -> line

set cl [exec clear line $line]

set ttyline [ios_config "line $line" "login authentication nologin"]

set transprt [ios_config "line $line" "transport input all"]

set sock [udp_open]

fconfigure $sock -remote [list $server $sudp_port]

after 1000

set IP "1.2.3.4"

set port [expr 2000 + $line]

set fd [socket $IP $port]

set counter 120

while {[gets $fd line] } {

incr counter

  if [ regexp {^\$GPRMC} $line ->line ] {

    if {$counter >= 120} {

      puts -nonewline $sock $line

      flush $sock

      send_syslog "NMEA packet sent to $server on port $sudp_port $line"

      set counter 0

    }

  }

}

[steven.anthony]

we've been trying to activate the new script for the past hour... doesn't seem that it is sending any data..

[Dan Frey]

It may be best to get on a web ex to go over these changes.   You can  reach me at dafrey@cisco.com and we can set up a time to take a look at this policy.

[sburton011]

I am in the middle of replacing 150 Sierra Truck cellular modems with Cisco IR829GW's and have noticed a significant increase in Cellular data consumption related to GPS data being send to out GPSGate vehicle location application. To the tune of 10x more data being send and at a streaming rate versus every 5 sec or 100M travelled. 

Is there a way to not use streaming or change streaming to only report an a scheduled interval like 10 sec's or do I have to resort to a script like you have here?

Ideally I would like the router to report in every 5 seconds when moving, or 100M travelled, and every 2 min when stationary.

NMEA Streaming is every second with data packets 2-4 times larger than Sierra and its going to drive out Cellular consumption.

Any suggestions are welcome. 

[manningnavcomp]

The script is the only way we have been able to get this to work.  We did have to remove the line:

send_syslog "NMEA packet sent to $server on port $sudp_port $line"

This caused the script to not work properly.  We could then change the 'counter' to get the desired report rate.

[sburton011]

What router platform are you running on? (IR800?)

Are you finding the 2 min interval is working for you?

Is you application a vehicle tracking one?

I appreciate the information.

[manningnavcomp]

Running on an Cisco 819 Verizon router.  The vehicle does not move very much, so it is only reporting every 5 minutes to the RASTRAC vehicle tracking service.

We did have to play with the counter a bit to get the proper report rate as the counter counts every message not just the RMC messages.  This gave us an approx. 5 min report:

set counter 3073

[sburton011]

Having issues getting this going. Am I right in assuming the router initiated the connection back to the server? I never see the router try to make the connection.

Here is my script:

package require udp
set server [lindex $argv 0]
set sudp_port [lindex $argv 1]
puts "server and port = $server $sudp_port"
set intf [ios_config "int loopback 1" "description DO NOT REMOVE" "ip add 192.168.252.129 255.255.255.255"]
set pt [exec show line | inc NM]
regexp {.?\s+(\d+)\s+TTY} $pt -> line
set cl [exec clear line $line]
set ttyline [ios_config "line $line" "login authentication nologin"]
set transprt [ios_config "line $line" "transport input all"]
set sock [udp_open]
fconfigure $sock -remote [list $server $sudp_port]
after 1000
set IP "192.168.252.129"
set port [expr 2000 + $line]
set fd [socket $IP $port]
set counter 120
while {[gets $fd line] } {
incr counter
  if [ regexp {^\$GPRMC} $line ->line ] {
    if {$counter >= 120} {
      puts -nonewline $sock $line
      flush $sock
#      send_syslog "NMEA packet sent to $server on port $sudp_port $line"
      set counter 0

    }

  }

My IOS commands are here:

event manager environment server "192.168.108.74"
event manager environment udp_port "30176"
event manager applet NMEA
 event syslog pattern "LINEPROTO-5-UPDOWN: Line protocol on Interface Cellular[0-9\/]+, changed state to up" maxrun 31536000
 action 010 cli command "enable"
 action 020 syslog msg "NMEA streaming starting now"
 action 030 cli command "tclsh flash:nmea_829_gps.tcl $server $udp_port"

Any ideas?

[Dan Frey]

You will not see anything on the router that it is making a connection to the NMEA server.    A few things to check.

Make sure the router successfully can reverse telnet to the TTY  port for NMEA (8 in output below).

C1921#sh line

   Tty Line Typ     Tx/Rx    A Modem  Roty AccO AccI  Uses  Noise Overruns  Int

      0    0 CTY              -    -      -    -    -     0      0    0/0      -

      1    1 AUX   9600/9600  -    -      -    -    -     0      0    0/0      -

      2    2 TTY   9600/9600  -    -      -    -    -     0      0    0/0      -

A 0/0/0    3 TTY              -    -      -    -    -     0      0    0/0    Ce0/0/0

* 0/0/5    8 TTY              - inout     -    -    -     0      0    0/0    NM0/0/5

I use this TCL script to act as my NMEA server.   

#!/usr/bin/tclsh

# A simple UDP server

package require udp

proc udpEventHandler {sock} {

    set pkt [read $sock]

    set peer [fconfigure $sock -peer]

    set dat [exec date +%H:%M:%S.%N]

    puts "$dat $peer: [string length $pkt] $pkt"

     return

}

proc udp_listen {port} {

    set srv [udp_open $port]

#    fconfigure $srv -buffering none -blocking 0 -translation binary

#   fconfigure $srv -buffering none -encoding binary

    fileevent $srv readable [list ::udpEventHandler $srv]

    puts "Listening on udp port: [fconfigure $srv -myport]"

    return $srv

}

set sock [udp_listen 12345]

vwait forever

##########End

Start server and wait for NMEA traffic.   

[root@HammerHead nmea]# ./tcl_udp_server.tcl

Listening on udp port: 12345

14:21:54.496828145 192.168.0.1 55488: 68 $GPRMC,180245.0,A,3854.406476,N,07810.006597,W,1.7,3.2,270417,,,A*78

14:22:46.490448749 192.168.0.1 55488: 69 $GPRMC,180337.0,A,3854.388506,N,07809.996212,W,1.3,82.4,270417,,,A*42

14:23:39.497720327 192.168.0.1 55488: 70 $GPRMC,180430.0,A,3854.373288,N,07810.005838,W,0.7,175.7,270417,,,A*71

14:24:33.523844220 192.168.0.1 55488: 69 $GPRMC,180524.0,A,3854.386612,N,07810.006207,W,0.0,86.7,270417,,,A*47

14:25:26.513996143 192.168.0.1 55488: 69 $GPRMC,180617.0,A,3854.386246,N,07810.004374,W,0.0,86.7,270417,,,A*46

[sburton011]

Reverse Telnet looks like its happening: Line 7

STJ-TEST-KEN#sh users
    Line       User       Host(s)              Idle       Location
   0 con 0                idle                 00:18:01
   3 tty 3                Async interface      00:00:00
   7 tty 7                incoming             00:00:00 192.168.252.129
 705 vty 0                idle                 00:24:19 EEM:NMEA
 706 vty 1     admin      idle                 00:25:40 192.168.101.130
*707 vty 2     admin      idle                 00:00:00 192.168.101.130

  Interface    User               Mode         Idle     Peer Address

I get nothing back on my server.

[Dan Frey]

Manually reverse telnet to the NMEA line and verify that NMEA data is present.

C1921#telnet 192.168.0.1 2008

Trying 192.168.0.1, 2008 ... Open

$GNGSA,A,2,67,75,76,85,86,87,,,,,,,1.1,0.7,0.8*2C

$PSTIS,*61

$GPGSV,3,1,12,07,46,313,48,08,67,168,41,09,49,253,38,11,14,172,33*79

$GPGSV,3,2,12,16,31,056,40,23,38,202,31,26,08,068,36,27,59,063,40*7E

$GPGSV,3,3,12,51,,,40,21,03,036,,28,00,254,,30,10,303,*44

$GLGSV,3,1,09,86,59,108,33,76,59,019,37,75,28,085,30,87,21,175,29*66

$GLGSV,3,2,09,85,28,035,32,68,02,343,34,66,16,240,,77,23,307,*66

$GLGSV,3,3,09,67,21,295,*50

[sburton011]

Its there:

STJ-TEST-KEN#telnet 192.168.252.129 2007
Trying 192.168.252.129, 2007 ... Open
$GNGSA,A,3,07,09,21,,,,,,,,,,500.0,500.0,500.0*24
$GNGSA,A,3,,,,,,,,,,,,,500.0,500.0,500.0*29
$GPGSV,2,1,07,07,37,305,22,09,24,262,18,21,23,049,20,30,02,314,24*74
$GPGSV,2,2,07,04,,,,08,52,223,,11,05,198,*73
$GLGSV,3,1,12,,,,24,77,16,314,17,76,73,343,13,87,11,202,20*5B
$GLGSV,3,2,12,67,07,302,16,68,08,351,19,74,,,,66,,,*6D
$GLGSV,3,3,12,86,66,180,,75,45,119,,84,,,,85,48,040,*52
$GPGGA,183730.0,4733.508324,N,05245.174442,W,1,03,500.0,62.9,M,12.0,M,,*75
$PQXFI,183730.0,4733.508324,N,05245.174442,W,62.9,558.07,955.22,19.60*7B
$GNGNS,183730.0,4733.508324,N,05245.174442,W,AN,03,500.0,62.9,12.0,,*4E
$GPVTG,,T,,M,,N,,K,N*2C
$GPRMC,183730.0,A,4733.508324,N,05245.174442,W,,,270417,0.0,E,A*13
$GPGSA,A,3,07,09,21,,,,,,,,,,500.0,500.0,500.0*3A
$GNGSA,A,3,07,09,21,,,,,,,,,,500.0,500.0,500.0*24
$GNGSA,A,3,,,,,,,,,,,,,500.0,500.0,500.0*29

[Dan Frey]

The script tries to get the NMEA port automatically by running CLI command "show line | inc NM".   The platform that I have used the NMEA TTY port was always on that port.   I suspect maybe your platform may not have that so the regex does not match.

For testing remove these two lines in the TCL script.

set pt [exec show line | inc NM]
regexp {.?\s+(\d+)\s+TTY} $pt -> line

Add this single where the two removed lines used to be so the TTY port is hardcoded to 7

set line 7

Also can you paste the output of "show line"

[sburton011]

STJ-TEST-KEN#sh line
   Tty Line Typ     Tx/Rx    A Modem  Roty AccO AccI  Uses  Noise Overruns  Int
*     0    0 CTY              -    -      -    -    -     0      0    0/0      -
      1    1 TTY   9600/9600  -    -      -    -    -     0      0    0/0      -
      2    2 TTY   9600/9600  -    -      -    -    -     0      0    0/0      -
A     3    3 TTY              - inout     -    -    -     0      0    0/0    Ce0
      4    4 TTY   9600/9600  -    -      -    -    -     0      0    0/0      -
*     7    7 TTY              - inout     -    -    -     8   1307    0/0    NM7
      8    8 TTY              -    -      -    -    -     0      0    0/0    Ce1
    1/3   69 TTY   9600/9600  -    -      -    -    -     0      0    0/0      -
    1/4   70 TTY   9600/9600  -    -      -    -    -     0      0    0/0      -
    1/5   71 TTY   9600/9600  -    -      -    -    -     0      0    0/0      -
    1/6   72 TTY   9600/9600  -    -      -    -    -     0      0    0/0      -
*   705  705 VTY              -    -      -    -   23     3      0    0/0      -
    706  706 VTY              -    -      -    -   23     1      0    0/0      -
*   707  707 VTY              -    -      -    -   23     2      0    0/0      -
    708  708 VTY              -    -      -    -   23     0      0    0/0      -
    709  709 VTY              -    -      -    -   23     0      0    0/0      -

Line(s) not in async mode -or- with no hardware support:
5-6, 9-68, 73-704