6.6. EFJohnson Console Protocol

This document describes the steps necessary to configure an Eventide NexLog recorder to record and playback radio traffic from an EFJohnson radio system. These steps are in addition to any standard source independent steps to configure the NexLog recorder, such as adding license keys, etc.

6.6.1. Configuring an Eventide Recorder to capture EFJohnson multicast P25 traffic

Source audio from the EFJohnson radio system can arrive at the recorder in one of two formats depending on the radio system type and configuration. P25 Radio Channels will transmit the audio using the IMBE codec. IMBE is a popular codec used on P25 radio systems. Analog Radio channels may instead transmit the audio using the G.711 codec. Eventide NexLog recorder supports recording either codec, including hybrid systems providing some channels in analog and some in IMBE.

If IMBE channels are to be recorded, the NexLog will require a vocoder device to be configured. On playback, the NexLog will send the IMBE audio to the vocoder device to be decoded prior to sending the audio to the client. This is not necessary for G.711 audio, which can be fully decoded internally by the NexLog recorder.

There are two supported vocoder devices supported by the Eventide NexLog recorder. The first is a DVSI Net-2000-VCU, which can decode up to four simultaneous streams of unencrypted IMBE for playback. The other option is to use an EFJohnson Atlas/JEM server to perform the decoding. In addition to providing a much higher capacity than the DVSI decoder, the JEM server can also decode encrypted EFJohnson audio streams, if the radio system’s keys have been loaded into the JEM server. If the EFJohnson radio system to be recorded contains encrypted IMBE traffic, only a JEM server will allow playback, and the DVSI vocoder cannot be used.

This document will describe how to configure the Eventide NexLog recorder to capture the EFJohnson radio traffic as well as how to configure it to use the correct vocoder device. This document will also describe how to configure the DVSI-Net 2000 for use with a NexLog. If the radio system being set up utilizes the Atlas/JEM server instead, this part of the instructions should be ignored and the JEM server set up instead. Installation and configuration of the EFJohnson Atlas/JEM server is beyond the scope of this document.

6.6.2. Configuring the DVSI Net-2000 VCU vocoder

Note

If an Atlas/JEM server is to be used for decoding the IMBE audio, or if only G.711 audio is being recorded, this section can be skipped.

6.6.2.1. Discovering the IP address of the DVSI Net-2000-VCU vocoder

Your vocoder comes preconfigured to use DHCP to connect to a network. The IP address can be discovered using two methods.

Method 1: Using NetBIOS to determine the IP

  • Use a Windows computer on the same subnet as the vocoder box.

  • Open a command prompt.

  • ping net2k0169 (where 0169 is replaced with the last four digits of the serial number.)

  • A reply should be received showing the IP address of the vocoder box.

Method 2: Using a RS-232 cable to determine the IP

  • Attach the included RS-232 serial cable between the DVSI Net-2000 and a Windows computer

  • On the Windows system run the HyperTerminal program

  • Choose the appropriate COM port for your system

  • Set the connection to 9600 baud, 8-bits, no parity, 1 stop bit, no flow control. Hit the Enter key

  • At the “adsh>” prompt type “network” and hit enter

  • The IP address should be shown

6.6.2.2. Configuring the DVSI Net-2000-VCU vocoder

Using the IP address from the vocoder above:

  • Select FILE MODE

  • Select APCO Enhanced from the drop-down box

  • select Start FILE Mode button

6.6.2.3. Configuring the Eventide NexLog to capture multicast P25 traffic

Step 1: Determine the address of the Eventide NexLog recorder after connecting it to the network

  • Use the Front Panel touchscreen interface on the recorder

  • Select the menu button on the lower-left corner

  • Select Setup

  • Select System

  • Select System Info

  • The IP address will be listed on the page

  • Adjust the network settings

Step 2: Set a static IP on the Eventide NexLog recorder

  • Use the Front Panel or a web browser pointed at the IP address discovered above

  • Navigate to Networking->Network Interfaces

  • Select Static from the Type drop-down box and change the IP address as needed

Step 3: Configuring EF Johnson RoIP capture

Either the Front Panel or a web browser can be used to configure the RoIP virtual board. The following instructions are for a desktop browser, which is the recommended method:

  • Open your browser (Internet Explorer, Firefox, Chrome) and go to the IP address of the recorder

  • select the Configuration Manager icon

  • When prompted, login with factory default credentials. Username: Eventide, password: 12345

    Note once installation/configuration is completed, Eventide recommends changing the default admin account to utilize a stronger password

  • select the Recording menu item on the left

  • Select Boards

  • select the Add Virtual Recording Interface button

  • In the Channel Count drop-down select the number of channels you want to add. This number should be less than or equal to the number of Local VOIP/RTP Channel licenses

  • Select the Local IP radio button

  • Select EFJohnson Console Protocol in the template drop-down box

  • Select the EFJOHNSON CONSOLE PROTOCOL tab

  • Select the Ethernet device that is connected to the network with the RTP traffic

  • Enter the IP address of the EFJohnson Atlas/JEM server or DVSI Net-2000-VCU in the IMBE Transcoder IP field. (Only one IP address can be entered here. If there are multiple IP addresses they can be added later.)

  • Select “DVSI NET-25 (Transcode at Playback)” to decode IMBE audio if that is what is available. (Note the DVSI cannot decrypt encrypted radio traffic.)

  • Select “EFJ JEM2 (Decrypt and Transcode at Playback)” to leave the audio on the recorder’s RAID as encrypted (if incoming audio is encrypted). The recorder will use the JEM server to decrypt the radio traffic and also transcode it at playback time. Because the audio will be encrypted at all times and only decrypted when playback occurs, this setting is more cryptographically secure, however, the decryption keys must remain available in the JEM server for the life of the audio. If a key is removed or changed on the JEM server, the NexLog will no longer be able to playback audio encrypted with that key.

  • Select “EFJ JEM2 (Decrypt at Record, Transcode at Playback)” to use the JEM server to decrypt the incoming radio calls and store them unencrypted on the RAID. It will then use the JEM server again to decode the calls on playback. If no encrypted audio will be used on the EFJohnson radio system, either option will work, but this one is recommended.

  • It is likely the Default RTP Port field can remain 20000,30000, but it can be changed to match your configuration.

  • Normally only a single transmission can be present on a given EFJohnson channel at a time. However, in the case of Console Preemption (Talkover) of an emergency radio call, the console performing the preemption may still be able to hear the radio audio being preempted, though other positions cannot. In this case, a single channel can be sending multiple audio feeds. To record both feeds, at least one channel should be dedicated to call preemption by entering TALKOVER in the IP address field. This channel will then be used as a destination channel for preemption audio. This will allow both the original call and the preempting call to be recorded at once. The number of TALKOVER channels configured determines the maximum simultaneous number of preemption call pairs that can be recorded.

  • Enter the multicast addresses for each channel. On some older EFJohnson systems a single channel may utilize multiple multicast addresses. If this is the case, enter the two IP addresses separated by a space. More recent EFJohnson radio systems utilize two ports (20000 and 30000) on a single multicast address to accomplish this instead, in which case this is not necessary. Note that only audio transmitted over a configured multicast group will be recorded. Audio sent via Unicast or Supergroup will not be recorded.

  • In the Codec drop-down for each channel select whether the channel will be recording P25 IMBE traffic or G.711 uLaw traffic

  • select the Save button

  • select the plus sign (+) next to “Local Ip Recording (EFJohnson template)” to display the channels for the virtual board

  • select the TIMEOUT column header and select “Set All Values -> Timeout” from the drop-down menu

  • Move the slider to the left until it displays “1 Sec.”

  • select the TIMEOUT column header again and select “Insert Col.”

  • select on the UNSET column header and select “rtp dtmfFieldName” near the bottom of the list

  • select on the RTP DTMFFIELDNAME column header and select “Set All Values -> rtp dtmfFieldName.”

  • Type TG_ID into the entry field and press Enter

  • Note: Only one EFJohnson virtual board should be created per system

Step 4: Modifying settings after initial configuration

  • After configuring the recorder with the desired number of channels using a template, you can make future changes to the template by navigating to the Boards page in the Configuration Manager, selecting the EFJohnson board, changing the template, and selecting the “ReApply Template” button. Note that if the template is reapplied any manual changes made to the board or board’s channels outside of the template prior to the reapply will be overwritten by the template application.

6.6.2.4. Configuring multiple DVSI Net-2000-VCU or EFJohnson Atlas/JEM servers

The Template for the EFJohnson Virtual board allows the configuration of the IP of the JEM or DVSI vocoder server as a convenience. If more than one vocoder is to be used, however, the following steps must be performed to configure more than one vocoder. If more than one vocoder is to be used the recorder will utilize both in a ‘round robbin’ method, sending a certain number of calls to one, and then to the other in a back and forth pattern:

  • Login to the Configuration Manager interface

  • Select the System menu on the left side of the screen

  • Select Configuration Files

  • Choose Vocoder Configuration from the list and select the View/Edit File button

  • Multiple DVSI Net-2000-VCU can be configured by just adding the IP address of each system on a separate line, for example:

    • 192.168.2.100

    • 192.168.2.101

  • To set up an EFJohnson Atlas/JEM server to decrypt on record on channels 1-12 and transcode on playback for all IMBE recordings:

    • 192.168.2.102 JEM2 1-12

  • To set up an EFJohnson Atlas/JEM server to decrypt and decode the recordings at playback time:

    • 192.168.2.102 JEM2

  • Advanced To set up an EFJohnson Atlas/JEM server to decrypt on channels 1-12 when the recordings are finished (decrypt only) and utilize a DVSI box for decoding instead:

    • 192.168.2.102 JEM2_DECRYPT_ONLY 1-12

    • 192.168.2.100

6.6.2.5. Playing back recorded IMBE calls

Recordings can be played back from either the Front Panel under Replay mode, via the MediaWorks application, or via the MediaWorks Express web application. Please consult the user’s manual for more information.

In MediaWorks Express it is possible to determine how a call in the data grid is currently stored on the recorder by right selecting the data grid header and turning on the ‘compression’ setting. Calls recorded for playback using a DVSI device only will list ‘IMBE’ here, calls recorded for JEM decoding, but currently stored as encrypted will be EFJ_RAW, and calls recorded for JEM decoding that is already decrypted will be ‘IMBE NOFEC’. MediaWorks windows application will only show ‘unknown’ for JEM calls.

Calls recorded for JEM usage will initially always be EFJ_RAW (even if unencrypted). If configured to decrypt at record time they will be queued up for batch processing and changed to IMBE NOFEC as the JEM server decrypts them (the same process can be observed for unencrypted calls, but the JEM server is not utilized in this case, the change happens internally to the NexLog). Vocoder Related Recorder Alerts.

There are two NexLog Recorder Alerts that can be raised by the NexLog relating to the vocoders. Either a DVSI or JEM Server can result in a “Recorder Timeout” alert if the recorder sends audio to the JEM server for processing and gets no response within a few seconds. If the timeout was due to offline decryption, the recorder will automatically periodically retry the decryption. If the timeout was due to online decoding (playing a call in MediaWorks) it will be necessary to restart the playback by double selecting the call in the data grid or pressing stop and then play in the transport, once the cause of the timeout is resolved. The most common causes of timeout alerts are lost packets on the network between the recorder and vocoder, or if the vocoder is unreachable on the network because it is powered down, configured for the wrong IP address, etc.

The second alert is raised only when using a JEM server. Each call received from the EFJohnson radio system will contain a header declaring whether the call is unencrypted, encrypted using the DES algorithm, or encrypted using the AES algorithm. If encrypted, it will also contain the KeyID of the key on the JEM server that should be used to decrypt the call. If the JEM server is not loaded with a key for that KeyID, the recorder will raise an alert about the invalid KeyID and will not be able to decrypt that call. Note that if a key of that ID is loaded on the JEM server but the key is incorrect, the recorder has no way to detect this and the JEM server will decrypt the audio incorrectly and it will not be intelligible on playback, but no alert will be raised.