Rangecast FAQ
[FAQ-1345] PC and Network Requirements for a Rangecast Feed Site


Page Type: REFERENCE


OVERVIEW

PCs called "Rangecast feed site PCs" connect scanners to the internet. Each PC typically supports 4 or more scanners. This document lists system, network, and operational requirements for Rangecast feed site PCs, and also covers the process for procurement of preconfigured PCs or setup of customer-supplied PCs.


EXCEPTIONS

This document relates to PCs that capture scanner audio, not to PCs where the Rangecast player is used to listen to scanner audio.


REFERENCE

1) PC REQUIREMENTS

a) EXCLUSIVE USE OF PC: A Rangecast feed site PC must be dedicated to this single application, and not used for any other purposes. This is because, if the PC is put under any significant CPU load from another application, Windows may not dedicate sufficient resources to the real-time audio processing that is necessary for Rangecast to capture audio. The result is major quality problems with the audio that is distributed to the Rangecast player, often making the audio essentially unusable. To prevent this problem, Rangecast has a firm policy that feed site PCs must not be used for any other applications. (In addition, this also eliminates any risk that other use of the PC might introduce viruses or change the PCs configuration in some way adverse to Rangecast operations.)

b) SYSTEM REQUIREMENTS: The primary factor driving system requirements for a Rangecast feed site PC is Windows' ability to maintain seamless audio recordings (dedicating sufficient real-time resources to record audio without any interruptions.) This primarily relates to CPU resources, but there may also be bottlenecks in PC subsystems such as USB that create limiting factors. In general, it is advantageous to eliminate background applications (such as anti-virus software) that can create spikes in CPU usage, since these can limit the resources Windows makes available to the audio recording process. Hard drive capacity requirements are negligable (nearly no space is used), although there is a fair amount of wear from the churn of temporary files generated in the recording process, so hard drives should have good reliability. Memory use is also fairly small.

c) ANYDESK: For maintenace, we find it extremely valuable to have remote desktop access to Rangecast feed site PCs. This is beneficial for occasional repairs, and diagnosing hardware or operating system issues. We use a customized version Anydesk remote desktop software that ties into our Anydesk account.

d) SCANNER MASTER SOURCED PCs: Scanner Master, a vendor affiliated with Rangecast, sells PCs that have the Rangecast setup pre-installed. This is the recommended way to obtain a fresh PC, both because the software setup is already complete, and because the PC hardware has proven reliable for Rangecast operations. (A few PCs -- especially Dell Optiplex -- have problems in their USB or audio systems that can create significant performance issues when connecting to scanner radios.)


2) NETWORK REQUIREMENTS

a) NOT AN INTERNET SERVER: A common misconception is that the Rangecast feed site PC is an internet server (probably since it generates audio that is heard on the Rangecast player, and customers imagine that the player is connecting over the internet to the PC monitoring the radio.) By definition, a server is a computer that accepts incoming network connections. The Rangecast architecture does not work this way. When a PC records audio from a radio, that audio is uploaded to Amazon Web Services cloud storage. The Rangecast player accesses AWS cloud to retrieve that audio. Since Rangecast feed site PCs are not internet servers, there are no special network considerations related to accessibility from the wider internet, and PC performance is not related to the number of people currently listening to that audio.

b) FIREWALLS: Rangecast feed site PCs should operate behind a firewall (not be directly exposed to the internet), for example behind a NAT firewall found in ordinary routers. In the current era, the use of firewalls is essentially ubiquitous, so this is the normal mode of operation for any PC. The rangecast feed site PC is NOT a server -- there are no outside network connections made to the PC from the Rangecast player or any other external source, all network traffic is outbound only (to standard ports 80 or 443.) So there is no need for port forwarding, exposing the PC directly to the unfiltered internet, or any special network or firewall configurations. If you can access https://www.google.com in a browser, and your network bandwidth is not extraordinarily low, the network conditions should be sufficient for operations.

c) CO-LOCATED PCs ON THE SAME LAN: At some receive sites, two or more PCs are used to operate a large number of radio scanners programmed to receive the same broadcast channels. In this case, the PCs must be placed on the same local network (LAN), and there will be network traffic between the PCs as the Rangecast software dynamically coordinates the tuning of these radio receivers (the Multisync feature.) Since this communication is entirely within the LAN, there are no special network considerations, none of this traffic passes through a firewall.

d) NO NEED FOR STATIC IP ADDRESSES: Rangecast feed site PCs do not need a static IP address, on either the WAN (internet) or LAN (local network.) There is no inbound traffic to the PC from the internet, and threfore no need for a static WAN address. Multisync may generate some local traffic between co-located PCs on the same LAN, but the Rangecast software on each PC reads its LAN address, and the Rangecast servers provide current LAN address information to peer PCs that need to communicate on the LAN, so there is no need for a static LAN address. The remote power switch recommended by Rangecast (WebSwitch) to reboot frozen PCs makes no network connection to the PC under its control, so that is not a factor. Normal DHCP works fine.

e) DNS RESOLUTION: The Rangecast feed site software must be able to resolve DNS for rangecast.com, google.com (used to test network connectivity), and Amazon Web Services. Rangecast software will not work in IT environments where DNS resolution is not permitted. (This is a rare issue, and only encountered in corporate environments where users are not permitted to freely access the Internet over their network connection.)

f) NETWORK BANDWIDTH: Internet connectivity should be solid, in our experience wifi can be unreliable in both bandwidth and stability of connections. Performance may vbe affected by other users of a corporate network, if shared with other high-demand uses (such as transport of video in TV newsrooms) Rangecast may falter during spikes of activity from other operations on your network if its capacity is sometimes pressed to its absolute limits. But there is no problem with sharing a network connection with other PCs engaged in ordinary levels of network activity. Upload bandwidth is more important than download bandwidth, since audio files are the largest source of data transfer, and these are outbound to cloud storage. We can't quote a specific minimum bandwidth, but to give a sense of the order of magnitude (Rangecast uses very little bandwidth), to support audio upload there should be at least 0.1 Mbps of upload bandwidth per radio or audio source. For example, an eight-scanner feed site should have at least 0.8 Mbps of upload bandwidth available. We don't know exactly how much overhead is required for retries or other functions, and we can't guarantee performance on a site where the bandwidth is running close to this threshold value. But in general, any decent internet connection will far surpass these requirements. Performance can be checked at speeedtest.net or other third-party bandwidth test websites.


3) OPERATING SYSTEM

a) WINDOWS OPERATING SYSTEM: Rangecast is compatible with Windows 7 and 10. We recommend using Windows 7, because we believe that it is a more stable operating system than Windows 10. However, either operating system can be used for a Rangecast feed site PC. There is a history of Microsoft forcing updates onto Windows 10 PCs that break some critical aspect of the operating system. Therefore, users of Windows 10 must accept an elevated risk that their Rangecast services may cease working correctly without notice, and possibly without a quick resolution. In additon, Windows 7 offers more control over how/when Updates are executed. While the risks associated with Windows Update is low, we believe that it is high enough to justify a recommendation that customers use Windows 7 for better system stability.

b) SAFETY CONSIDERATIONS: If used correctly, Rangecast feed site PCs pose an extraordinarily low risk for viruses or other software infections, because the PC is used for only this one application and operates behind a firewall. This should be taken into account when evaluating the use of protective measures such as Windows Update and anti-virus software. (Aside from the third-party Anydesk software, the only network connections outside your LAN are to the Rangecast servers, our storage in the Amazon cloud, and sometimes Google for the purpose of testing network connectivity to a third-party website.) For reasons discussed below, both Windows Update and anti-virus software come with some degree of performance risk that should be balanced against the benefits of these services.

c) WINDOWS UPDATE: While we understand the benefit of regular Windows Updates, it should be understood that Updates interrupt the operation of the PC for a period of time while the update is applied. This will necessarily result in some downtime on the radio scanners under the control of the feed site PC. Regular Windows Updates are easy for office PCs dedicted to particular users, because there is no cost to downtime for Windows Updates while the employee is at home. But for PCs that normally operate 24/7 in production use, such as Rangecast feed site PCs, the outage caused by each Windows Update may be disruptive to the customer. In addition, in our experience PCs sometimes freeze (blue screen or similar) following Windows Updates, and do not recover until power cycled. For these reasons, it is worth considering reducing the frequency of Windows Updates, or even not running Updates if this is an option in your environment. But if you wish to run frequent Windows Updates (or you use Windows 10 where they are mandatory) this is perfectly acceptable.

d) ANTI-VIRUS SOFTWARE: In our experience, anti-virus software can destroy the performance of a Rangecast feed site PC. Due to the nature of Rangecast operations, our software generates a rapid churn of temporary files (for example, audio recordings.) Anti-virus software that attempts to evaluate the safety of every file appearing on the PC can consume significant amount of CPU resources inspecting these temporary files. Rangecast depends on Windows reliably devoting certain resources towards real-time audio processing, and CPU spikes from anti-virus software can steal resources needed to record seamless audio, resulting in audio missing short sections of time, rendering it unintelligable. While anti-virus software is good in principle, in practice the inspection of temporary files can render the product worthless. In borderline cases, the symptom will be occasional unintelligable audio with a cause that is not obvious (it will just sound like bad reception.) Therefore, we strongly recommend that any anti-virus software on a PC be configured to exclude our software (SENDER folder on the desktop) so it does not expend CPU resources on inspecting these temporary files.


4) SETUP OF CUSTOMER-SUPPLIED PC

a) CUSTOMER SUPPLIED PCs: If you supply your own PC to serve as a Rangecast feed site PC, you will need to have Rangecast remotely perform a PC setup (install software and device drivers, and configure the Windows user account.) For this process, you must first install Anydesk remote desktop software from the Windows user account that will be used for Rangecast operations (see FAQ 1323), and you must ensure that this Windows user account has administative permissions. Then you must supply Rangecast with the following information: The nine-digit Anydesk ID (shown by the Anydesk installation script); the name of the Windows user account (user name) if there is more than one on the PC (we strongly discourage multiple accounts); and (if created) the password for that account. Then you must ensure that the PC is turned on, connected to the Internet, and Windows is configured to not enter a sleep or hibernation mode during periods of inactivity (we can't access the PC if it shuts itself down.) It is strongly recommended that the PC have only a single Windows user account, and that this account not require a password to login, because this eliminates issues related to automatic launch of software in the user account when the PC reboots while unattended.


[FAQ-1323] Installing Anydesk on a fresh PC (no Rangecast software loaded)

Anydesk is remote desktop software used by Rangecast to access PCs. When a fresh PC (no Rangecast software is installed), the first step is installing Anydesk, so that Rangecast can then access the PC to install software and configure/verify various aspects of the Windows environment.




b) WINDOWS REGISTRY: For historical reasons, the Rangecast software was developed to not write to the Windows Registry. Instead of an installer package, Rangecast uses a "light-weight" deployment process involving files that reside on the desktop. (We also place one file in a Windows folder to trigger auto-launch on startup, and install third-party drivers as necessary for the external hardware and remote desktop access.) In general, excepting the autolaunch script and a desktop launch shortcut, the entire Rangecast software package is found in the SENDER folder that resides on the desktop.

c) PC SETUP PROCESS: Setting up a Rangecast feed site PC involves more than simply putting the Rangecast files into place on the desktop. We also install device drivers, prepare the software to autolaunch on startup, and configure various Windows options that enable both more reliable performance and create a standardized environment for diagnostics and maintenance instructions. We originally allowed anyone to set up PCs, but found that -- even with clear instructions -- most PCs were setup with errors that eventually resulted in performance or diagnostic problems that could have been avoided with a clean PC initial configuration. Therefore, for quality control we presently have a single highly trained person set up all Rangecast feed site PCs, and this person is familiar with slight differences needed to accomodate variations in particular Windows installations. This PC setup process is ususally done overnight within 24 hours of a request being processed by your Rangecast customer representative. (If you supply a PC for setup, and we find that either the Windows user account or Anydesk installation was not done to Rangecast specifications, you will need to repair the issue and resubmit the setup request.)

d) COPYING FILES INSUFFICIENT: Do not attempt to set up a Windows PC for Rangecast by copying Rangecast's files from another feed site PC. First, this will not be a complete setup, because it omits the configuration of the Windows operating system and user account, and the installation of device drivers. In addition, some of the files in the SENDER folder contain unique identifiers for the PC or scanners, and when copied to another PC can create identity conflicts within the Rangecast system.

e) WITHOUT ANYDESK: Our specifications state that remote desktop access via Anydesk is a required element of our technical support. If Anydesk cannot be used on the PC (for example, if IT policies prohibit the use of remote desktop software allowing unattended access from outside the corporate network, or if we must interact with IT staff to setup a remote desktop session), you should understand that you are taking on the responsibility for maintenance of the Rangecast feed site PC, and for diagnosing and repairing any technical issues that may arise in the future. We do not prohibit this configuration, but we also don't support PCs in this configuration. Even if your IT policies prohibit the use of Anydesk on PCs inside your corporate network, Anydesk installation is mandatory for the setup of a customer-supplied Rangecast feed site PC. You are responsibile for both installing Anydesk and putting the PC on a network (such as an internet connection outside your corporate network) where you do not prohibit the use of Anydesk, until we have completed the PC setup.

f) BIOS SETTINGS FOR POWER-UP: Most PCs have a setting in the BIOS (a more fundamental part of the computer than the Windows operating system) that controls the behavior of the PC hardware when power is applied or restored. Your PC must be configured so that the PC will automatically power up when power is applied or restored, so the PC will recover automatically from power outages. (If this is not set correctly, the PC will remain powered off following a power outage, until someone from your organization manually goes to the PC and presses the ON button. This can result in a signficant service outage.) This configuration setting is made in the BIOS, and cannot be done from the Windows operating system, so we have no way to remotely configure this specific aspect of your PC. And since the specific way of setting this option depends on the specific model of your PC, we cannot supply instructions. The BIOS setting is a customer responsibility if a customer-supplied PC is used for a Rangecast feed site.


5) WINDOWS USER ACCOUNTS

a) RANGECAST ACCOUNT: When a PC is setup for use as a Rangecast feed site, the Rangecast software is placed in the folder of a specific Windows user account, and that user account is customized in various ways. After this is done, changing Rangecast's operation to a different Windows user account on the same PC will require a re-installation of the software (a new PC setup), which will come with an additional setup fee, since the work has to be redone.

b) AUTOMATIC LOGIN: It is strongly recommended that Windows be configured to automatically login on bootup into the Windows user account used for Rangecast. Rangecast feed site PCs run an automated service (no user at the keyboard), and for various reasons will occasionally need to reboot without manual supervision. This creates a problem if ANY user interaction is required to login on bootup to the Windows user account used for Rangecast. The PC should not ask the user to choose a Windows user account (e.g. choose from multiple accounts on the PC), or ask the user to enter a password to access the Windows user account used for Rangecast, or ask the user to manually accept a Terms of Service agreement.

c) SERVICE MODE: If the PC is unable to automatically launch the correct Windows user account on bootup, the Rangecast software will need to be operated in a special "service mode" (also known as "session zero") that runs in the background without the Windows user account being logged in. This mode of operation is not intended for applications, but for background services (such as basic network connectivity.) It can be done, but will make the Rangecast operation on the PC far less intuitive if there is a need for maintenance. So although this is used where automatic login is impossible due to IT constraints, this mode of operation is strongly discouraged. Every effort should be made to make the PC login automatically to the Windows user account used for Rangecast without any user action from the keyboard/mouse.

d) ADMINISTRATIVE PERMISSIONS: Windows user accounts can be either "administrator" or "standard" accounts. (This is not a reference to the name of a Windows user account, but a level of permissions granted to a user account.) Windows user accounts with administrative permissions have a greater level of control over the PC and operating system. Some IT departments prefer to isolate user applications into "standard" accounts without administrative access, so unvetted software that might be installed by a user can't change basic aspects of how the operating system or hardware is configured, or affect how the PC works for other user accounts on the same PC. Therefore IT may elect to grant administrative authority to users only when necessary. However, it is important for the Windows user account running Rangecast software to have administrative permissions on the PC. Rangecast's core function involves interaction with hardware (audio inputs, USB system, etc), and standard (non-administrative) Windows user accounts are limited in their ability to configure or manage PC/hardware interfaces. Also, it is impossible for us to perform the initial setup of a customer-supplied PC without administrative permissions. For both PC setup and ongoing maintenance, we need to have Windows administrative permissions on the PC to efficiently diagnose and repair simple hardware issues that may arise from time to time. Since there are no other users on the PC, it is appropriate for Rangecast to have this level of control over PC operations.

e) PASSWORD: If the password to the Windows user account hosting Rangecast is changed, and we don't get the updated password, we will be unable to maintain the PC or diagnose issues. Therefore, if the password is ever changed, Rangecast must be notified. If we do not have a current username and password for accessing the Windows user account, you will be responsible for all maintenance and diagnostic work.

f) SINGLE ACCOUNT: In general, it's recommended that the Windows PC have a single user account. This simplifies the login process (no need to choose an account), and since the Windows user account used for Rangecast should have administrative permissions, there is no need for separate administrator-level and standard-level accounts. Pre-configured Rangecast feed site PCs shipped by Scanner Master have a single Windows user account, and it's recommended that this configuration be maintained (or if a customer supplies their own PC, that it be set up similarly.)


6) REMOTE POWER SWITCH AND POWER BACKUP

a) WEBSWITCH: PCs sometimes freeze, and must be power cycled to resume normal operations. While infrequent, such events can be a major problem for automated services such as a Rangecast feed site PC (no user at the controls to immediately notice and restart the PC). This is the leading cause of downtime in Rangecast services (the PC at a customer location freezing and therefore not feeding audio until someone manually corrects the issue.) To avoid this problem, we recommend the installation of a remote power switch called "Webswitch" -- this is a network-connected device that can interrupt the power to the PC on remote command. Webswitch units do not require a static IP or receive network traffic; instead they poll our servers every 60 seconds, and if our system detects that the PC has gone silent, our servers will command the Webswitch to automatically power cycle the PC. This allows for automatic recovery of frozen PCs without any long service outage and without manual work necessary at the customer site. (This is especially valuable when PCs are stationed in offsite locations with good conditions for RF reception, but no on-site staff.)

b) UPS: If power is lost at a location, obviously WebSwitch (which also runs on electricity) will not keep the PC online when there is no power. A UPS is recommended for this purpose. Since Rangecast's operations depend on internet connectivity, routers or other network infrastructure should also be operating on a UPS for maximum reliability.


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