Product Manual
ACCESS MultiRack Manual I. Introduction 12 Applications 12 Audio Coding 12 Transmission Modes and Delay 13 Switchboard Server 13 CrossLock 13 Additional Features 14 AES67 Protocol 14 HTML5 14 II. Diagrams and Installation 15 Rear Panel Diagram and Descriptions 15 Front Panel Diagram and Descriptions 16 Mono vs.
Iii. Quick Start - Connections With MultiRack 20 More About Profiles 20 Using The Console 20 About MultiRack Instances 21 Making Switchboard Connections 21 Receiving Incoming Connections 22 iV. Using The Device Manager Program 23 Updating Firmware Using Device Manager 25 Network Recovery Mode 26 V.
Utilization Graph 33 CrossLock Settings 34 Profile Manager Tab 35 Building a Profile 36 Profile Settings: Local & Remote Encoders 36 Advanced Local & Remote Options 37 Instance Settings Tab 39 Security Settings 40 Connections 40 Contact Closures 40 Switchboard Server 41 Alternate Modes 41 Advanced Instance Settings 42 Auxiliary Serial 42 Switchboard Server 42 Advanced Instance Settings Under Alternate Modes 42 BRIC Normal Settings 42 HTTP Settings 43 Modem (Instance 1) 4
Vi. Global Settings and Network Manager Global Settings CrossLock VPN Settings 46 46 46 AES67 System Settings 47 Advanced Global Settings 47 Advanced CrossLock VPN Settings Network Manager Tab 47 48 Ethernet Port Settings 49 Network Locations 50 WLAN Adapter 50 3G/4G Connections 51 Advanced Ethernet Port Settings 52 VIi.
Outputs ViIi. Making CrossLock Connections How CrossLock Works: A Brief Overview Multiple Network Setup 57 59 59 60 IX. Making Connections Via Switchboard 62 X. Making Manual Connections 64 Creating New Remotes 64 Backup Remote 65 Connecting And Disconnecting 66 Special Notes for Manual CrossLock Connections XI.
XII. Operating MultiRack In A 24/7 Environment 80 Always Connect To 80 Backup Remote 81 XIII. POTS Connections 83 Pots Codec Setup for MultiRack Compatibility 83 Using MultiRack With POTS 83 Rate Drop vs. Retrain 83 Troubleshooting A POTS Connection 84 XiV. About The Algorithms 86 AAC 86 HE-AAC 86 HE-AACv2 86 Linear PCM* 86 FLAC* 87 G.722 87 Opus 87 Algorithm Codec Profiles Chart 88 XV.
MultiRack Rack Receives the Call Using CrossLock with Multistream Connections 90 90 XVi. IP Multicast 91 Multicast Profiles 91 Setting Up a Multicast Remote 92 Time-To-Live 92 Changing Port Numbers for Multicast 92 XvII. Streaming Server Function 93 Decoding a Stream 94 Simultaneously Connecting MultiRacks And Streaming 94 XVIII.
Making Registered SIP Calls 98 Advanced EBU3326/SIP Topics 98 SIP Troubleshooting 99 Outgoing Call Issues 99 Incoming Call Issues 99 Solutions 99 Stunning Success 100 Fix of Last Resort 100 XiX. License & Warranty Disclosures for MultiRack 101 License 101 Warranty 102 XX. Switchboard Traversal Server Disclaimer Traversal Server Disclaimer XXi.
APPENDIX B: IP Compatibility 112 APPENDIX C: Unidirectional Networks 114 Standard RTP Settings 114 Decode Side Settings Only 114 Encode Side Settings Only 114 Full-Time Or Triggered Connections 114 APPENDIX D: Information For IT Managers 115 Incoming Services 115 Outgoing Services 116
ABOUT COMREX Comrex has been building reliable, high-quality broadcast equipment since 1961. Our products are used daily in every part of the world by networks, stations and program producers. Every product we manufacture has been carefully designed to function flawlessly, under the harshest conditions, over many years of use. Each unit we ship has been individually and thoroughly tested. Comrex stands behind its products.
I. INTRODUCTION Congratulations on purchasing the Comrex ACCESS MultiRack codec! The MultiRack leverages the core functionality of the original ACCESS Rack, which was first introduced in 2006 and quickly became the world’s leading IP audio codec. The MultiRack carries the ACCESS line forward, promoting an entirely new hardware and software platform. The MultiRack provides an elegant way to move high-quality linear or compressed audio over sub-optimal networks with very low delay.
Transmission Modes and Delay The MultiRack is a true codec, offering a full-duplex stereo encoder and decoder in each unit. When two-way transmission is not required, the reverse channel may be disabled. The BRIC Normal technology incorporated includes a jitter buffer manager that automatically balances delay and stability, dynamically increasing and decreasing delay based on network performance. For networks where QoS is known, these parameters may be set to maintain a consistent level of jitter buffer.
Additional Features AES67 PROTOCOL AES67 is an Audio-over-IP (AoIP) protocol designed as a replacement to the XLR connector. Uncompressed audio is sent and received via Ethernet Network and routed across the studio through an AoIP routing system. AES67 is an industry standard that most proprietary AoIP routing systems will accommodate. HTML 5 Previous firmware versions for Comrex codecs provided a web-based control page powered by Adobe Flash.
II. 1 MULTIRACK DIAGRAMS AND INSTALLATION 12 2 3&4 5&6 7 8 9 10 11 13 14 Figure 1 Rear Panel Diagram and Descriptions 1 AC Input - An IEC connector for the main power. MultiRack works on worldwide AC power at 110-240 VAC 50-60 Hz, auto detecting. 2 Analog/AES3 Input Switch - This switch determines whether the Line In Left/AES3 In XLR connector is used for analog or AES3 digital audio input. 3 Analog Audio Input Left/AES3 - Apply balanced analog audio to be sent over the network here.
15 16 18 17 Figure 2 Front Panel Diagram and Descriptions 13 Contact Closure Input/Output (Instance #1) - Provides four sets of contact closure inputs and outputs, which can be used to initiate outbound connections, or send signals to the far end of the link to trigger remote control gear (e.g., automation equipment). 14 Serial Port (Instance #1) - RS-232 serial port for ancillary data access. 15 Send - Each instance has a single multi-color LED for Left and Right channel.
mono vs. stereo Regardless of whether audio input is configured as analog, AES3, or AES67, MultiRack uses its left channel input only for encoder Mono Modes. The right channel is omitted. Output audio is available at both the left and right outputs in decoder Mono Modes.
Instance #2 IDI0 IDI1 IDI2 IDI3 IDO1 IDO2 ID03 ID04 CC in #1 CC in #2 CC in #3 CC in #4 CC out #1 CC out #2 CC out #3 CC out #4 Instance #3 IDI4 IDI5 IDI6 IDI7 IDO5 IDO6 IDO7 IDO8 Instance #4 IDI8 IDI9 IDI10 ISI11 IDO9 IDO10 IDO11 IDO12 Instance #5 IDI12 IDI13 IDI14 IDI15 IDO13 IDO14 IDO15 IDO16 Inputs are triggered by shorting the respective input to any pin labelled GND.
External Serial Port 1 2 3 4 MultiRack Instance 2 3 4 5 Because USB-Serial converters are designed to connect to computers, these adapters break out to DTE-style (male) RS232 pinning. To attach to a PC or other DTE style ports, they will require null-modem adapters on each of the four RS232 DB9 connectors. We recommend Kingdee slim line adapter F/F model ADIB075XHWVSJ, available from online retailers.
iii. QUICK START-MAKING CONNECTIONS WITH MULTIRACK This section skips over many of the details concerning the configuration of remote connections with MultiRack, and focuses instead on the minimum information needed to establish a connection. MultiRack connections with and without use of the Switchboard server will be covered. MORE ABOUT PROFILES Refer to Page 35 for more information about creating profiles on MultiRack.
ABOUT MULTIRACK INSTANCES The web-based user interface opens to the control page for instance #1 on MultiRack. Instance #1 is unique because it’s the only codec instance capable of using the analog/AES3 audio I/O ports. The default for instance #1 is not to use these ports, but to use the AES67 Audio over Ethernet function instead. To change the instance used, select the hamburger “menu” button on the upper left side of the page, and choose an alternate instance to open the appropriate page.
FIGURE 5 SWITCHBOARD CONNECTIONS ICONS RECEIVING INCOMING CONNECTIONS By default, MultiRack is set to automatically answer incoming calls, whether or not Switchboard is used to make them. Incoming calls will appear in your connections list while they are active. They can be disconnected locally by highlighting them and clicking “Disconnect”.
iV. USING THE DEVICE MANAGER PROGRAM Firmware updates for the MultiRack should be handled using Comrex Device Manager, a Windows- and MAC OS-executable program that can be downloaded from the Comrex website. Device Manager can also be used for license installation and IP configuration. Please note: In order to configure an ACCESS MultiRack unit for the first time (without knowing the unit’s IP address), Device Manager must be run on a computer located on the same network (e.g.
Figure 8 Toolbox login Generally, it is recommended to configure the Ethernet port of an ACCESS MultiRack for a static IP. This will facilitate access to the Web-based Interface with a browser and allow for easier configuration of routers or firewalls (if necessary). If the MultiRack is to be installed on a managed LAN, Comrex recommends consulting with the IT services provider about obtaining a static IP address. As mentioned in the previous section, the MultiRack is configured for DHCP by default.
Figure 9 Network COnfiguration UPDATING FIRMWARE USING DEVICE MANAGER While Device Manager is open and synced to a codec, it’s a good time to check to see if an update is available for the product. To do this, select the Firmware tab, shown in Figure 10 below. The unit’s current firmware and the most recent version of firmware for the unit are listed at the top of the tab (1 in Figure 10).
1 2 3 Figure 10 Firmware tab NETWORK RECOVERY MODE Since the Ethernet settings are made with a web connection, keying in incorrect static IP information can result in losing access to the Network Manager interface entirely. If this happens, it is possible to be “locked out” of the unit (i.e., unable to log in). Device Manager has a network recovery tool to help with this: Network Recovery Mode.
Figure 11 network recovery mode 27
V. CONFIGURING THE MULTIRACK The MultiRack is primarily controlled by using a browser to access the built-in web server, which offers a HTML5 user interface page. Alternately, a similar page is displayed when a keyboard, video monitor, and mouse (abbreviated KVM) are attached to the rear panel of the MultiRack. This is called the Console Interface. The main differences between the console and the web-based interfaces are: 1) There are no audio level meters displayed on the console interface.
the five control pages, and selection can be made on-the-fly between them. It is only required to log into the aggregated page once, and each instance may be selected without added security logins. The aggregated page defaults to show the instance #1 options. The currently selected instance can be changed by selecting the menu (hamburger) button in the upper left corner of the page. A slide-out menu will appear allowing you to select which of the five instances are “in focus” on the browser.
• Configuration Tabs (2): The primary focus of the MultiRack configuration interface. These tabs consist of Connections, Dashboard, Audio, Profile Manager, and Instance Settings to control and obtain status of MultiRack. They are described in detail in the following sections. 1 2 Figure 14 Connections Tab CONNECTIONS TAB The Connections Tab is the first window in the configuration interface. This allows for monitoring device connectivity and controlling connections.
1 2 4 3 5 Figure 15 Dashboard Tab 1. The audio level meters give a quick indication of send and receive levels. 2. The Contact Closure section gives a visual indication of the state of each input (local) and output closure (remote). The input closure boxes also function as buttons to trigger closures locally. 3. The Active Connections section gives and indication of any currently active connections. If more than one connection is active, they will display in a list here. 4.
Figure 17 jitter/packet error graph The left graph represents the work of the Jitter Buffer Manager. The area of most interest is the light blue area as shown in Figure 17, which illustrates a spread of jitter values (referenced to the current play out pointer) over the last second. If this area covers a large span, the relative jitter is high. If the light blue section of the graph is small or invisible over a time period, less jitter is present.
The CrossLock Stats are similar to the information available on the Active Connections graph, which shows streaming performance without regard to the CrossLock layer. The CrossLock Stats show finer details about network performance in both directions than can be obtained through the Active Connections graph. CrossLock stats are shown for both the data being transmitted from the local codec and the data being received by the local codec. All relevant stats are available for both directions.
CROSSLOCK SETTINGS Clicking the CrossLock Settings field during an active connection will display the CrossLock sliders. There is a slider available for transmit and receive operation. For most CrossLock connections, the sliders should be left at their default Automatic Delay Mode settings. But during connections on unusual networks, these sliders are designed to quickly adjust the current delay settings. The sliders will reset when a CrossLock connection ends.
provide stability. These “zones” scale, increase and decrease in size based on the history of jitter experienced by CrossLock on the network. In “Auto Delay” mode, the dark dot signifies the “Current Delay”, which is the best compromise value calculated by the system to balance stability and delay. By changing the “Automatic Delay Mode” switch to manual, the “Target Delay” indicator can be dragged left or right to override the automatic settings, and increase or decrease the delay.
BUILDING A PROFILE To build a new profile, select Add New Profile (1 in Figure 24) and a new profile appears on the list labelled New Profile. Select it to populate a set of options, starting with the profile Name (2 in Figure 24). Here, the profile can be renamed to something easier to remember. Next is the Channel option (3 in Figure 24), which allows for selecting between a standard Comrex IP connection (BRIC normal) or one of the other connection modes offered by MultiRack.
time. The default is 60 seconds, but this can be shortened or lengthened as desired. If an indefinite connection is necessary, refer to Operating MultiRack in a 24/7 Environment on Page 80 for additional information. Encoder - It is unnecessary to define any decoder types when using ACCESS because they automatically adapt to the incoming stream. Using this menu, users can select the encoder used to send audio from this ACCESS (local) as well as the encoder used to send audio to this ACCESS (remote).
Retransmit Squelch Max - The longest period of data loss during which the squelch function is active. Default is two seconds. During the squelch period, the buffer manager ignored the relative jitter experienced and does not adjust buffer size to compensate. Fixed Delay - This option simply sets the Delay Cushion and Delay Limit at a similar value, so that the delay buffer is defined to the chosen value and will not increase or decrease significantly.
Congestion Avoidance - Enabling this option allows the encoder to dynamically change the number of frames per packet sent, thereby reducing total data requirements. In addition, in most encode modes, enabling congestion avoidance provides the system a license to step down to a lower encode data rate if desired. This will happen automatically and with no audio interruption. Step down congestion avoidance is not enabled in the Linear PCM mode.
SECURITY SETTINGS Remote Control Password - This allows for a defined password for the web GUI and firmware updates. The default password is comrex (lowercase). The remote control and firmware updating functionality can be disabled completely by disabling the Remote Control option. Although this option appears in the Instance config page, it is global in scope and will change the password for each instance. A warning is displayed to this effect.
remote. A connection attempt will be made whenever the contact is triggered, and will disconnect whenever the contact is released. SWITCHBOARD SERVER Switchboard Enabled - This option enables the use of Switchboard to connect to remote units. (See Making MultiRack Connections Using Switchboard on Page 62 for more information on using the Switchboard Traversal Server.) Server Address - The Internet URL of your Switchboard server. Default is the server maintained free of charge by Comrex.
ADVANCED INSTANCE SETTINGS When the Show Advanced Settings option is enabled, additional options and categories are displayed. AUXILIARY SERIAL Baud Rate - Allows for controlling the Baud Rate of the serial port. Default is set to 9600. Data Bits - Allows for the configuration of number of data bits. Default is set to 8. Stop Bits - Configures the number of stop bits. Default is set to 1. Flow Control - Allows for selection of the flow control method.
HTTP SETTINGS HTTP settings involve the built-in Shoutcast/Icecast-compatible streaming server built into MultiRack. Accept Incoming Connections - Users can set MultiRack to listen for and automatically answer any HTTP incoming requests. This option is set to No by default. IP Port - This option defines the incoming TCP port—the number to be used for incoming HTTP connections. The default is TCP 8000 for instance #1 for legacy purposes. Instance #2 defaults to 8002, instance #3 is 8003, and so on.
VIP QC Password - For legacy purposes with the VIP QC app, which has been deprecated. RTP IP Port - The port used for audio transfer during EBU3326/SIP mode. Since this port info is transferred during the negotiation process, it can be changed without breaking compatibility. Note: RTSP data is always sent and received on the port one number higher than this. Public IP Override - Allows setting of a discrete value of IP address used during negotiation. Used in challenging IT environments.
MISCELLANEOUS Meter Demo Mode - This setting will put the front panel LED meters into a demonstration mode. This setting is set to No by default.
VI. GLOBAL SETTINGS AND NETWORK MANAGER Some MultiRack settings don’t affect a single instance, or involve audio, network I/O, CrossLock, or other settings that affect the entire MultiRack. These settings are found in a different page, accessed by the main menu button on the upper left side of the Instance config page. Settings having to do with networks (aside from AES67 aspects) are contained in the “Network Manager” settings. All others are located in the “Global Settings” page.
Timezone - Users can set their Timezone in this setting. This allows for inputting a User’s Timezone by Region, Country, and Timezone. AES67 SYSTEM SETTINGS The basic options are described here. See the section on AES67 operation for details on this function. AES67 Enabled - Enables the use of the AES67 AoIP engine. This is Enabled by default. Instances #2-5 require AES67 to be enabled for audio I/O. Network Interface - Allows selection of which network interface should be used for AES67.
Permissive - Allows users to accept CrossLock connections from any unit. This is set to No by default. Authentication - Enables the authentication of connections. Default setting is No. Protection - Enables AES encryption and payload integrity protection to prevent tampering with or interception of the transmitted content. This option has a SIGNIFICANT system overhead. Default setting is No. Maximum Delay - Allows users to configure the maximum allowed target delay, in milliseconds. Default setting is 5000.
Figure 26 Network manager main screen The primary ethernet port for MultiRack is configured for DHCP by default. In this configuration, MultiRack will be assigned an IP address from a pool of available IP addresses from the network router upon booting. If MultiRack is connected to the Internet, it should display connection information for the Ethernet Port, including IP and DNS server addresses.
IP Type to open a drop down selection screen. This will give users the option to change the “Default” Network Location to Static IP, DHCP, or Gateway IP types as shown in Figure 28. Figure 28 ethernet port default settings NETWORK LOCATIONS While the “Default” setting may work for many users in a stationary environment, MultiRack includes Network Location settings for configuring different connections to different Networks known as “Locations”.
Figure 30 WLAN adapter settings When setting up a WiFi connection, users will require the use of a USB WiFi adapter to begin making connections. Once this has been installed, the adapter will populate in the Select Network Device section of the Network Manager Tab as the WLAN Adapter (Figure 30). This adapter must be Enabled prior to using or scanning it. The WLAN Adapter can be enabled by selecting it in the list and selecting “Enabled” under the Device Manager Settings and setting it to “Yes”.
Figure 31 4g Cellular modem settings ADVANCED ETHERNET PORT SETTINGS When Show Advanced Settings (in the lower left corner) is selected, the following options also appear: Preserve After Reset - This option ensures that changes to the unit’s network configuration will be preserved even if the device is reset to factory defaults. This setting is disabled by default, however, and Comrex advises users to be cautious when enabling it.
VII. AES67 CONNECTIONS AES67 is an Audio-over-IP (AoIP) standard for intra-studio audio routing. It’s not intended to be an out-of-studio distribution technique, but rather to replace the Analog/Digital audio ports with an Ethernet cable. This makes audio wiring simpler (via standard Ethernet cable) and moves the routing of audio into the networking domain. While AES67 is the standard, several pre-standard systems have gained popularity.
• Instance #1 on MultiRack can only be set entirely for AES67 or Analog/AES3 operation. It’s not possible to mix modes for input/output audio. All XLR ports on MultiRack are entirely disabled when instance #1 is in AES67 mode, including outputs. SETTING UP FOR AES67 AES67 settings are located in the Global Settings section in the Main Menu. Open the tab and choose the AES67 System options. This is shown in Figure 32.
INSTANCES Below the main AES67 settings are entries for the five instances. By expanding each of these options you can set which AES67 input is received, the name and address of that instance’s outgoing AES67 stream, and other parameters. ENABLE All AES67 channels are enabled by default. If you plan on using analog or AES3 audio I/O on instance #1, disable AES67 mode here. If you don’t plan on using an instance and want to turn off its output AES67 stream, set that instance to disabled here.
Figure 34 sdp settings Whether you’ve found your stream using discovery or manual SDP, once it’s selected, MultiRack will search your network for the stream and attempt to lock on to it. The status of this process is shown under the Input 1 header and should eventually show “Receiving RTP”. SETTING INPUT DELAY The default settings for AES67 input streams may work well for some streams, but often it’s important to manually set the amount of delay applied to the input stream in order to make it stable.
AES67 OUTPUT On MultiRack, an AES67 output stream is automatically created for each instance. This stream has the following parameters: • 2 channel • 48 kHz sampling • 1 ms packet timing • SAP and Ravenna Advertisement • Multicast destination address 239.1.x.x (Where x.
DSCP - This is a flag applied to outgoing packets that tells your switches about priority. The AES67 default is 34, and should be changed only when special requirements exist. Payload Type - This is a value sent in outgoing stream advertisements. AES67 default is 98. If your AoIP system has special requirements, it can be changed here.
VIII. MAKING CROSSLOCK CONNECTIONS ON MULTIRACK Comrex first introduced CrossLock—its technology that creates an additional reliability layer to ensure quality broadcast connections—with version 4.0 firmware in 2016. As an increasing majority of users updated their units to CrossLock-capable firmware, connections made using CrossLock became the norm for Comrex codecs and are considered standard in MultiRack and ACCESS Codec connections.
As shown in Figure 38, BRIC Normal connections happen over the CrossLock VPN Layer. The CrossLock connection between the Comrex hardware happens over a single port (9001), but the BRIC Normal connections take place virtually on their usual legacy ports within that VPN. The system will show these virtual connections happening on ports 9000, 9002 and 9003 (these are the BRIC Normal ports)—however, the only actual connection between hardware is happening on 9001.
Finally, CrossLock can be configured to use one network only when the primary network fails. This is called “HotSwap” mode and is described in a later section. As long as an incoming CrossLock call is possible on the primary network attached to a codec, the call may be initiated from the remote end of the connection. As an example, at a transmitter site the primary network is a DSL line, and port UDP 9001 (the default port for CrossLock connections) is open from the public Internet.
IX. MAKING CONNECTIONS VIA SWITCHBOARD ON MULTIRACK This section describes the procedure of making and receiving connection on MultiRack via the Comrex Switchboard server. This is the easiest way, but not the only way to make MultiRack connections. Before connections are made this way, you must set up and configure a Switchboard account as described in Section XI.
Once your Switchboard peers are configured, connecting to one is simple: 1. Select the desired Switchboard peer. 2. Make sure the “gear” icon is green. 3. Click “Connect” in the upper-right corner. Switchboard connections can be ended on either end of the link, by choosing the active connection in the list and clicking “Disconnect”. Incoming connections will appear as new entries in the Switchboard peer list while they are active. They can be disconnected the same way.
X. MAKING MANUAL CONNECTIONS Creating new Remotes When connections are added to the list manually, we call them “remote entries,” or “remotes” for short. To create a new remote connection, click on the “Plus Sign” (+) on the right of the screen (1 in Figure 40) to Add A New Remote Connection. This will bring up a dialogue box where a new remote’s parameters may be defined (Figure 40). 1 Figure 40 Edit Remote Settings Choose a name for the remote (e.g. WXYZ), followed by the IP address of the remote.
Figure 41 Profile manager tab Backup remote MultiRack features an ability to have an automatic backup to a designated remote connection. A specific backup connection (for when the primary fails) is designated when a new remote is created. As shown in Figure 42, selecting the backup option opens a menu allowing selection of other outgoing remotes that have been created.
CONNECTING AND DISCONNECTING Once the remote connection entry is completed in the Connections Tab, highlight the remote and select Connect. When a connection is attempted, the State column in the connection table will change to reflect the progress of the connection (Figure 43). If the connection fails, the reason for the connection failure will be shown in the State column. When the remote connection succeeds, the encoder and decoder mode will be reflected in the Rx Status/ Tx Status column.
XI. SETTING UP YOUR SWITCHBOARD ACCOUNT The Switchboard Traversal Server is a service built and maintained by Comrex on the public Internet that provides users a directory of other users, facilitating connections to devices that would normally have trouble accepting incoming IP connections. Use of Switchboard is free and comes activated from the factory. Use the instructions in the user interface chapters of this manual to configure Switchboard on the MultiRack unit.
Figure 45 switchboard unit list Creating Users It is possible to add additional Switchboard users who can access the Switchboard interface. This is done via the Users tab at the top of the main codec list (Figure 46). This allows for the creation of accounts for users that can later be deleted. Several user accounts can be created with unique passwords. Figure 46 users tab Contact Lists In some situations, it might not be desirable for every codec to see the Switchboard status of every other codec.
Figure 47 COntact list By default, a master Contact List is created that contains all codecs in an account. Every codec in the fleet uses the master list by default. For users uninterested in segregating codes on their account, the default configuration will work fine. NOTE: Assigning a Contact List to a codec determines what gets displayed in its own list. It does not have any impact on how that codec is displayed on other devices.
Figure 49 Unit Screen To follow a Contact List on a codec, first click on the “Details” button for that codec on the main screen in Switchboard (Figure 48). Next, press the “Change” button near the middle of the following screen (Figure 49). Figure 50 follow cOntact list On the next screen, check the Contact List(s) that you want this codec to Follow and press “Update Contact List” (Figure 50).
Figure 51 unit sharing tab Figure 52 share a device To create a Share, click the Sharing tab and then select “Add New Share” (Figure 51). The following screen then allows users to choose which codec(s) they want to include in a Share (Figure 52).
An email will then be sent from the server asking the user to confirm the Share. Once they’ve confirmed the Share, the Shared devices will appear as options in their contact list menu. Please note: Shares are a one-way transaction. For shares to work both ways, with each user able to view each other’s devices, both users must send each other a Share invitation and then each accept the other’s invitation (as illustrated in Figure 54).
Figure 56 multiple contact lists If multiple Contact Lists have been designated as “Followed“ on a unit’s Switchboard interface, each Contact List will appear at the bottom of the Connections tab (Figure 56). To view and/or connect to the unit(s) within a list, select the list and press the Open Folder button on the upper right.
Figure 58 bulk actions To do this, press the Bulk Action button in the bottom right corner of the Contact List tab (Figure 58). The three steps to create a Bulk Action are: 1. Choose the type of action to perform. 2. Select the codecs targeted with this change. 3. Identify the Contact List that will be impacted by the change.
Figure 60 Bulk device selection After completing this step, specify whether to target the units that are a part of a Contact List or the units that are Following that list (i.e., the option in the yellow-outlined box on the middle-left of the above figure). Note: Bulk Actions can ONLY be performed on ENTIRE Contact Lists. They CANNOT be performed on individual codecs or on a portion of a Contact List.
Switchboard Theory and Concepts Switchboard is useful because it’s not always simple to connect two devices, which are essentially “peers”, over the Internet. There are two major reasons for this. First, to initiate a stream to a device over the Internet requires knowing its IP address. This is the number that gets applied to the destination field of the IP packet, so Internet routers can determine how best to send it along its way. Every device that connects directly to the public Internet must have one.
The challenges of connecting codecs behind NAT routers will be addressed in more detail shortly. For now, remember that one of the problems NAT servers add is that private IP addresses delivered to codecs (and the only addresses of which the codecs are aware) have no bearing on the public addresses seen from the Internet.
can easily imagine the complications of obtaining or managing port forwarding on the LAN when arriving at a new remote venue. This would likely encounter a large amount of resistance or confusion on the part of local IT staff. In describing NAT routing, it’s important to understand the concept of ports. These are numbers, like the source and destination IP addresses that are attached to each packet. They further qualify which application on a computer (or codec) is meant to send or receive a packet.
Figure 64 bidirectional communication Switchboard aids in breaking through these different types of routers for incoming calls. Because it is in constant contact with all subscribed codecs, it can send and receive test patterns to determine whether one or more NAT routers exist on a link and what type they are. It can then choose a connection method to be used to circumvent any issues. Switchboard can: • • • Instruct the calling codec to make a normal connection (no NAT detected).
XII. OPERATING MULTIRACK IN A 24/7 ENVIRONMENT MultiRack can be configured for “always on” operation. This allows for constant STL communication and operations requiring long-term connections. In BRIC Normal mode (the default mode of operation), MultiRack transfers all its audio data via the UDP 9000 protocol. This is in contrast to most web-based connections like browsing and email, which use the bidirectional TCP protocol. UDP, unlike TCP, is not “connection oriented” (i.e.
Figure 65 always connect to setting Backup Remote MultiRack has an additional option for constant connections. When building a remote entry, a field is available for backup options—one of these options is “Keep Retrying This Remote” mode. In a similar fashion, using this mode will allow the unit to disregard the timeout value and keep a persistent connection attempt. The difference is that the Disconnect function still works and the connection will not be re-initiated on a power-up.
Additionally, there is a box in the Change Remote Settings tab labelled Automatically fall forward. If this box is checked, the system will constantly attempt to reconnect the primary remote while connected to the fallback remote. If connection is successful, the connection to the “Fallback” will be terminated.
XIII. POTS CONNECTIONS MultiRack is capable of connections over modem links. This mode emulates the function of Comrex POTS (Plain Old Telephone Service) codecs, which have been used for years to deliver high quality audio over standard, dial-up telephone lines. This mode provides for a point-to-point connection between the codecs (i.e., no Internet where MultiRack is used) and the call is placed directly from one MultiRack (or legacy codec) to the other.
Rate Drop and Retrain controls are similar in function to those provided on POTS codecs. MultiRack will initially connect at the best data rate supported by the telephone line, and will display this rate on the Connections Tab page. Figure 67 connections tab during an active pots call Selecting Rate Drop will force the system to drop to the next lowest connect rate at any time. Audio transfer will be interrupted momentarily while the units negotiate the new connect rate.
• At minimum, connect a few minutes before airtime to assess the connection quality. Setting a MaxRate on the POTS codec is highly recommended. MaxRate usually should be set at a level or two below the maximum unrestricted rate. This will provide a “guard band” against noise and distortion which may cause errors on the line. • If operation starts to degrade after a long period of connection, it’s possible the phone line parameters have changed.
XIV. ABOUT THE ALGORITHMS When building profiles for MultiRack and remote devices, there are several different audio encoder options to use for each direction of the link. Different audio encoder options each have advantages and disadvantages depending on the situation. The following is a refresher on audio codec algorithms to assist in making the best choice. AAC This algorithm is a highly regarded standard for compressing audio to critical listening standards.
FLAC* This encoder compresses audio data using a lossless algorithm. This means that the audio extracted from the decoder is identical to the audio input to the encoder, with no coding artifacts. FLAC typically removes 30-40% of the network data compared to Linear PCM, but the actual data rate is variable and is based on the complexity of the coded audio. Using FLAC over Linear PCM typically results in a slightly higher (5 ms) overall delay. G.
Algorithm Comparison Chart for ACCESS NX Rack AAC Required Bitrate Coding Delay Audio Bandwidth 64 kb/s 69 ms 20 kHz D1 Mono 96 kb/s 69 ms 20 kHz D2 Stereo 128 kb/s 69 ms 20 kHz D3 Dual Mono allows independent programming to be sent on both L&R channels 128 kb/s 69 ms 20 kHz D4 Stereo 128Kb 256 kb/s 69 ms 20 kHz D5 Dual Mono 256Kb allows independent programming to be sent on both L&R channels 56 kb/s 69 ms 20 kHz D6 Mono 56Kb 96 kb/s 69 ms 20 kHz D7 Mono 96Kb 160 kb/s 69 ms
XV. MULTISTREAMING MultiRack supports the ability to run one encoder per instance, but this single encoder stream may be sent to up to three destinations simultaneously. This capability is referred to as a Multistream, as the encoder creates a separate but identical outgoing stream to each decoder. (Note: A User’s Internet connection must be able to support these streams.
Multistreaming Arrangements The following includes two examples of Multistream arrangements involving the MultiRack. In the first environment, the MultiRack that is serving the Multistream initiates calls, and in the second, the serving MultiRack accepts all of the incoming connections. MultiRack initiates the call In the “Multistreamer as caller” model, two different profiles will be built on MultiRack A.
XVI. IP MULTICAST IP Multicast is an efficient way of delivering MultiRack digital audio streams to multiple locations. This involves relying on the network to distribute the stream to the locations that require it, rather than creating an independent stream for each user. Performing an IP Multicast requires the use of an IP Multicast-capable network. The commercial Internet, with few exceptions, is not capable of supporting IP Multicast. Some private LANs and WANs are IP Multicast capable.
The important settings for Multicast are: • • Sender/Receiver - Determines whether this particular MultiRack is designed to generate and encode the IP Multicast stream (send) or decode one (receive). Encoder Type - Determines the algorithm format of stream to be used by the Multicast encoder—not relevant for decoders. In addition to the basic options for IP Multicast profiles, clicking the Advanced box will allow setting of the same Advanced Options available for Normal BRIC (Unicast) profiles.
XvII. STREAMING SERVER FUNCTION MultiRack has the ability to act as a streaming server, delivering AAC and HE-AAC to compatible PC-based media players. Currently tested media players include WinAmp, VLC, and Windows Media Player 12 and up. By default, streaming server functionality is turned off. To enable it, go to the System Settings tab of the User Interface and choose HTTP Settings option. Under the first option, set Accept Incoming Connections to Enabled (Figure 72).
The Genre, Info URL, and Public options may be set for anything, or left alone. These options, if applied, will be embedded into the stream. Decoding a Stream To decode a stream, open one of the supported players and select the option to open a URL-based stream. In Winamp and VLC, input the address of the MultiRack in the following format: http://192.168.0.
XVIii. MAKING EBU3326/SIP COMPATIBLE CONNECTIONS Comrex codecs (and many other brands) have a set of protocols that allow easy IP connections between units. In general, when connecting between Comrex hardware, it’s best to use these proprietary modes to take the most advantage of the features of the product. However, many users are concerned about getting “locked in” to a certain codec brand.
EBU3326/SIP Modes A function of placing a SIP-style call is the ability to register with a SIP server. This is a server that exists somewhere on the network, usually maintained by a service provider. Several free servers exist that can offer registration, like Onsip.com. The MultiRack allows EBU3326/SIP calls to be placed or received with or without registration on a SIP server.
• The password on the SIP account. Figure 74 shows how this information can be applied—by enabling the Use SIP Proxy option under EBU 3326/SIP on the Systems Settings tab. Figure 74 EBU3326/SIP Settings Once this information is correctly entered, a new field appears in the “Registration Status” box located on the Connections tab (Figure 75). Figure 75 Sip status The status will reflect the progress of the registration process. When complete, this will display Online.
Making Registered SIP Calls When registered, calls made using an EBU3326/SIP profile behave differently than normal. The address field, regardless of whether it is a SIP URI or an IP address, is forwarded to the server. No connection attempt is made until the server responds. If the server accepts the address, the call will be attempted. If not, an error message will appear in the status line. Possible reasons for call rejection by a server are numerous.
same as the server/proxy address, and if this field is not populated, that is the default. If, for some reason, the domain is different than the server/proxy address, then this field is used. SIP Troubleshooting In a nutshell, SIP establishes a communication channel from the calling device to the called device (or server) on port 5060 (instance #1).
Solutions Many times the “return address” field issue is fixed by the SIP server (in Registered mode) and no compensation measures are necessary. Often, the server insists on acting as a “proxy” and handles all the traffic itself. Outgoing and incoming streams are relayed directly by the server, solving any router issues. In point-to-point connections this isn’t possible, and some hacks are required to make this work.
XIX. LICENSE & WARRANTY DISCLOSURES FOR ACCESS MULTIRACK Licenses MPEG-4 audio coding technology licensed by Fraunhofer IIS http://www.iis.fraunhofer.de/amm/ ACCESS uses proprietary and open-source software programs. Some of the open-source programs are licensed under the Gnu Public License (GPL). For more information on GPL see http://www.gnu.org. As per the GPL, source code for this software is available on request from Comrex on CD-ROM or other electronic format.
Further copyright notice for ncurses, dropbear PuTTY and libxml2 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copy
The next two paragraphs apply to all software contained in this product: WITH THE EXCEPTION OF THE WARRANTIES SET FORTH ABOVE, THE PRODUCT (MEANS COLLECTIVELY THE HARDWARE AND SOFTWARE COMPONENTS) IS PROVIDED STRICTLY “AS-IS.” COMREX CORPORATION AND ITS SUPPLIERS MAKE NO WARRANTY, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR WARRANTY AGAINST LATENT DEFECTS.
XX. SWITCHBOARD TRAVERSAL SERVER USE DISCLAIMER TRAVERSAL server disclaimer You have purchased a product from Comrex that uses the Switchboard TS (Traversal Server) to provide the ability to locate Comrex hardware via the Internet and to aid in the making of connections when certain types of NAT routers are involved in the link.
XXI.
EC Declaration of Conformity for R&TTE Directive We: Manufacturer’s Name: Comrex Corporation Manufacturer’s Address: 19 Pine Road Devens, MA 01434 hereby declare on our sole responsibility that the product: Comrex ACCESS MultiRack Digital Audio Codec to which this declaration relates is in conformity with the essential requirements and other relevant requirements of the R&TTE Directive (1999/5/EC).
U.S. and Canadian Regulatory Information for the ACCESS MultiRack This equipment complies with Part 68 of the FCC rules and the requirements adopted by the ACTA, as well as the applicable Industry Canada technical specifications. On the bottom of this equipment is a label that contains, among other information, a product identifier in the format US:DXDMD01BACCRK. If requested, this number must be provided to a U.S. telephone company.
APPENDIX A - HOTSWAP MultiRack instances are able to utilize Hotswap, allowing users running CrossLock in “Dual Network” mode to designate a primary and secondary network. This secondary network (e.g. wireless 4G) serves as a back up to the primary in case of network failure. Hotswap is a Global setting in MultiRack. This means the system requires that all instances use “Hotswap” mode simultaneously, or none do. There’s no way to configure HotSwap for use on only one instance.
assumes no liability for data overage charges, even in the event of software bugs or any other failure of hardware or software. It is entirely the responsibility of the user to monitor any metered data usage. Setup Setup for HotSwap is done entirely on the end of the link that has dual networks connected. On the MultiRack, the best way to set up HotSwap is via the Network Manager page, accessible via the web-based interface.
Select “Save Settings”, then click “Close” or press ESC to exit Network Manager. Reselect the Main Menu and navigate to the Global Settings page. Under CrossLock VPN, locate the entry labelled “Redundant Transmission” (Figure 79). Change this from the default “Off” to “On”, and then click “Apply Changes”. Figure 79 CrossLock redundant transmission Finally, set one of the contact closures to sound an alert when the HotSwap function is engaged. Still in the CrossLock settings, select “HotSwap CC unit”.
Figure 81 Hotswap CC indicator 111
APPENDIX B - IP COMPATIBILITY The MultiRack is capable of encoding and decoding a choice of three different types of non-MultiRack streams: Standard RTP, Luci Live and Zephyr Xstream. The choice is exclusive— i.e., you must set the MultiRack specifically for the type of stream you wish to be compatible with and you will remain incompatible with the other two types unless you change it. This setting has no effect on normal MultiRack functions, which continue to operate as before. 1.
• Outgoing Connections - Build a profile using the Profile Manager on the MultiRack and select a Channel Mode of Standard RTP. Then choose an Xstream-compatible encoder for the outgoing call. The Xstream will control what type of stream, if any, is returned to the MultiRack. 3. Standard RTP - This mode is set to receive a basic, unformatted AAC stream within a standard RTP/UDP structure. At present, this mode does not offer compatibility with other industry devices.
Appendix C - MultiRack on Unidirectional Networks Under most circumstances, MultiRack requires an IP path in both directions for successful connections, even when audio is being sent only one-way. For networks that provide data only in one direction, it is possible to use Standard RTP mode to establish and maintain these links. This section describes how to set that up. The codec has several compatibility modes under the Standard RTP channel mode.
APPENDIX D - Information for IT Managers The purpose of this appendix is to describe all open ports and services available on the Comrex MultiRack. The Comrex MultiRack is a device designed to move real-time, wideband audio over IP networks. The main network interface is 1000BaseT-Ethernet. The device contains an optimized version of Linux kernel. The IP parameters are set by a computer on the local LAN using a proprietary broadcast UDP protocol.
Outgoing services Service NTP Switchboard STUN DNS Lookup 116 Destination 0.comrex.pool.ntp.org:123 (UDP) switchboard.comrex.com:8090, switchboard.comrex.com:8081 (secondary) (TCP) stun.comrex.