Introduction

Welcome to my manual for doing things at robotics competitions. I've been running IT and operational logistics for robotics competitions for over a decade now, and this manual contains the collected wisdom I've learned the hard way.

Note that this manual outlines workflows that I've found work for me, but that you may need to make adjustments to anything you learn here to make them work for you. Also keep in mind that you're reading here about the refined outcoe of many years getting things wrong, so expect that you'll need to do some trial and error and optimizing to suit your own workflows and processes.

Networks

There are many reasons to consider running a network for a BEST Robotics competition. You may want to locate scoreboards further from your scoring table than video cables allow. You may want to use direct-entry digital scoring, or make use of your network to connect judgest with PCSM in a different room. You may just want to browse memes while waiting on a team to find the field despite being paged 5 times already.

Whatever the reason, there are some considerations to make when running a network for BEST:

• Will you use the venue/house network?
• Will this network be internet connected?
• Who's equipment will be used? (Own vs. Rent)
• Will general volunteers have access?
• Will you provide connectivity to your teams?
• What applications will you use on your network?

We'll go through each of these points, and then look at two possible network architectures that you can use depending on the size of your event.

Venue and House Networks

As a general rule, you should not be using the venue or "house" network. Unless you personally are the IT that owns and operates that network (and even then you should really have BEST in a partition for so many reasons) you should not use the house network. This is because the house network is configured for the needs of the organization that owns and operates it, not BEST. This usually means that point-to-point connectivity is disabled or heavily filtered, addresses are not static or arranged for quick adjacency, and there may be other traffic or users present on the network.

The one thing you can use the house network for reliably is a WAN or Internet connection. This puts the untrusted network on the other side of a firewall from all BEST things, and makes the request to the venue much simpler. If you want to get internet from your venue, the magic request is usually a hard-line network connection supplied with DHCP, and with port-security disabled since you'll be providing a downstream router. Some venues will initially question the use of a downstream router, it is important to explain the unique technical challenges of BEST Robotics, the need for strict control of access to the network, and the ability to rigorously test everything days and weeks in advance of your game-day. If your network is sufficiently portable, you may even wind up bringing it with you to your practice or exhibition days, something that would be impossible to do with a specific venue's network.

Will You Have Internet?

Internet connectivity is extremely handy to have, and can make it much easier to retrieve materials from the BRI file manager, allow you to publish scores in real time, or allow you to use OSM for retrieval of advancement inputs.

Internet should always be supplied on a cable or network hardline. Generally you'll be connecting to an existing network and not provided directly with a public address, so you'll be stacking NATs. This is not ideal, but is comletely workable in most venues. Coordinate with venue IT to ensure you won't have the same address space on each side of your NAT.

Who's Equipment Will Be Used?

The complexity of most BEST events far exceeds that of the humble linksys router. Therefore, you'll need to gain access to some more suitable equipment. Later in this document you'll learn how to use the Gizmo FMS in a mode that provides you with a robust network for scoring and similar functions, but if you want a network that spans a large physical campus (such as a high school with courtyards) you'll need some more hardware. Consider carefully whether this is a prudent investment, or if it would be better to solicit either a donation in-kind from an IT firm, or find a volunteer who may "rent" you this equipment on a daily basis.

To put down some ballpark figures, the network equipment used to run Dallas BEST which covers a single large Gymnasium and 2 classrooms is approximately $250 invested across a substantial router, selection of cables, access point, and a nice case to protect the equipment. Moving up in scale, Capital BEST which in most years spans 2 Gyms, 3 Classrooms, a large Cafeteria space and usually a large lecture hall makes use of a substantial amount of equipment and cable, on the order of $2000 in equipment total. At the large end, Texas BEST which lights up service in the Texas Fair Park Collesium makes use of roughly $15k in network equipment, cable, and the associated hardware to transport, deploy, and crucially un-deploy over such a large footprint.

Do not underestimate these costs, but also understand that the largest cost is always the human one. BEST is an all-volunteer organization, and having hardware does you no good without skilled volunteers to understand the unique challenges that BEST poses, and our stringent requirements for success. You should expect that a skilled engineer who can provide their services commercially will run in the $250-$300/hr range. Many are willing to donate their time since BEST is on a mission that resonates with many industry professionals, but be aware the effort being asked of your volunteers.

Who Will Have Access?

Having a network opens up the question of who will have access to it. In general your scorekeepers will need to have access, but may not themselves need to know network passwords or access codes. You can simply pre-provision computers for them to use, or input these keys yourself.

In the author's experience, its usually okay to permit trusted volunteers to have access to the network, though usually this is accompanied by a short lecture (<20 seconds) about not sharing this access and being careful. If you intend to have general volunteers on the network, it is important to ensure that your scoring manager instances are secured using strong passwords, that your Gizmo FMS is protected by firewalls, and that you still be selective in how you actually provide volunteers with access.

If you intend to provide teams with access, it is imperative that they be isolated to a distinct VLAN and if possible distinct VRF. Teams must be considered untrusted actors on your network that represent and imminent security threat. While it is unlikely that any team would intentionally do harm, this is a risk you simply cannot afford to take, and can defend against without substantial effort.

When your network is receiving internet from your host venue, its a good idea to double check if there are any strings attached to the use of the host venue's internet. Many academic institutions receive their internet connections from vendors that put restrictions on how they can be used, and as a downstream consumer, you must abide by these restrictions if applicable. This can restrict out of the gate who has access, as many universities and schools will request you to have only "mission critical" entities on the network. Fortunately such places usually also provide a guest network for your attendees to use.

What Applications Will Be Available?

The entire point of having a network is to enable various applications to be used across multiple computers. There are several applications that are in common use across BEST, and some less common. Here are some of the most common and things you may need to consider:

• PC Scoring Manager (PCSM) and Pi Scoring Manager (PiSM) - These are the meat and potatoes of the robot game. They run locally and provide services directly onto the network. It is important for these services to be protected by strong passwords. Consider sourcing a dedicated computer for running the scoreboard, or run it as part of an approved and validated architecture, such as the hub-in-a-box architecture.

• Pitman - This paperless pit management application is meant to assist with check-in, machine compliance, and general pit management. It is a web application that can be accessed from either a computer or tablet connected to your network. It should be protected by a strong password per its operating instructions, but isn't necessarily as critical as the scoring system itself.

• PCSMPages - This is an add-on service which provides additional web-pages for PCSM that are designed to support video production work. They are designed to be luma-keyed into other scenes and provide lower thirds with team information, as well as a paginated scoreboard. These pages can be open to the network as they do not contain any sensitive information.

• Matchclock - Matchclock is a dedicated clock display that plays start of match, end of match, and a 30 second warning sound. It is designed for video production work and can be luma-keyed into a larger source view or displayed on dedicated displays. Most deployments of matchclock provide a tablet or other device for the head referee to use to start the match clock, so that a seperate position of timekeeper is not required.

• Gizmo FMS - This Gizmo FMS itself is a substantial consumer of network services, which is why it contains its own network. Its mentioned here to call out that the robot control networks that teams connect to using the cables at the driver's positions should always be treated as seperate and for that purpose only. The FMS provides an auxiliary network that can be used for non-robot concerns, and this is the only network that should be used for such concerns.

• Open Broadcast Studio (OBS) - OBS is a standard tool in the toolbox of anyone looking to stream video to the internet. This is a free software tool that takes in cameras, various media sources, an even web-pages and allows you to switch between them, composite them into scenes, and then stream the entire thing out to the internet for viewers who can't make your event in person. Setting up and using OBS are well beyond the scope of this document, but OBS can be economically setup by using PoE Security Cameras which can be very economically sourced. Being network security cameras, they obviously need a network. Its generally not necessary to take any special precautions while using something like OBS on your network, but if you intend to work at extremely high resolutions (4k or greater), carefully consider if this bandwidth usage will impact other applications.

Building a Network

We've talked through a lot of items, considerations, and use cases for having a dedicated network at a BEST Robotics event. Lets now look at concretely how this may be achieved. We'll look at 3 network architectures. Its extremely important to understand that, with the exception of the Gizmo FMS network, these are bespoke and purpose built for the events and needs that consume them. Network engineering is not a one-size-fits-all process, and carefully documenting your requirements and approach to solving those requirements are the first steps to success.

Keep this in mind as you review each of the following examples, and review these examples more as ideas than concrete implementations you should try to duplicate.

Small Network

For small events, such as those consisting of a main competition space with adjacent pits, the Gizmo's FMS Auxiliary Network may be all you actually need. This is the "Infrastructure Network" that you are prompted about in the setup screens, and is broadcast at 5Ghz from the field radios. This is in a different band than any of the robots and will not interfere with them. In general though you should still try to plug in any laptops that you intend to use. The FMS network port (port 2) on the scoring table box is the source of this network, and you can get additional ports by connecting a dumb/unmanaged ethernet switch to this port if required.

This kind of network is suitable for cases where you just need a little network, and you don't need it to be particularly advanced.

Visually, this is what this network looks like:

Its quick, its using equipment you already have, and it can supply a modest event with all the services that are required and then some. The Gizmo FMS network is also a good starting place to determine what youre requirements are, since it gives you enough to get started and determine what else you might require.

Medium Network

For larger events such as those that supply private network connectivity to judges rooms, volunteer spaces, and other ancilliary areas, a more substantial network is required. This network will be larger in 2 dimensions: the services that are offered and the physical footprint.

To enable more services to be offered, its time to add a small form factor server that's not a laptop. This will live with the core router and switching equipment. For logistics reasons, its recommended to set this equipment up wherever your pit administration area is since that's usually the first area that's up and the last area to come down. An SFF PC chassis running a basic Linux is a good choice for an event server since all applications that you may wish to deploy to it are available as Docker containers. Do not be scared by it being called a "server". This just refers to it being a dedicated machine that has no monitor and that nobody sits in front of. Once you configure the applications you want, there really isn't any additional configuration to be applied.

To be physically larger is just a matter of adding more ethernet switches, more wireless access points, and more cable. When running more than one access point, its a good idea to use a managed access point which can coordinate device roaming, otherwise you'll see issues when a device is in range of more than one access point and it cannot firmly consider one to be a better signal. If running a fully external network from the FMS, you should use externally managed access points. Aruba Instant access points are a good choice for this and can be had on ebay for little money. These access points self-host their control plane on whatever access point boots up first, and provide an intuitive web interface for configuration.

Let's look at the Capitol BEST network and the various components:

Not pictured are several wireless belt-pack phones, various laptops connected in various locations, and the entire Gizmo FMS network that is behind the Gizmo router.

There are several things worth calling out in this network:

• Phones! Capitol BEST makes use of a private telephone network to quickly and efficiently communicate point to point. We have both fixed phones and wireless phones for key staff. Usually we'll equip the pit admin, hub director and head referee with phones directly. This allows, for example, the head referee to effortlessly contact the pits without leaving the field. The phones are something that work well for Capitol BEST, but do not work for everyone and take some training to use.

• Several links are optical. Each of the links above that's listed as 1000BaseSX is an optical fiber. We use these fibers since they can go up to 1600 meters without additional hardware, whereas ethernet tops out at 100 meters. While that's 300 feet (approx.) keep in mind that many schools in the Texas Hill Country have large courtyards, and a single courtyard can be in excess of 300' across.

• Several links are referenced as Peering. These links are router-to-router links where we've configured the routers on each side to be aware of each other so that their address space is directly accessible. If you don't know what this means don't worry, its an optimization that helps us to coordinate this larger network.

This is a network that did not spring into existence overnight. Years of optimization, evaluation, and figuring out what does and doesn't work went into this architecture, and its extremely tightly aligned with the way that the team behind Capitol BEST works.

Huge Network

Sometimes you need to go big. Either by choice or requirements, building a huge network is not for the faint of heart, and this is firmly the territory where you need an actual network engineer who knows what they're doing to save you from peril and expensive mistakes. A large network will be characterized by the raw throughput, physical scale, and vast array of services and requirements that it fulfills. For this network example, we'll dive deep into how the Texas BEST network is put together.

Texas BEST is a championship-scale event supporting more than 85 teams across 3 divisions and a rookie bowl, as well as various other functions such as a mascot dance off, robot parade, and high production environment. The Texas BEST network is also installed into a historically protected fairground which has functionally no infrastructure of its own. Close coordination with event media and AT&T is required to pull off a successful deployment. The network depicted here supports several key requirements:

• Total aggregate throughput in excess of 5Gbit/s. This is the fastest service that AT&T reasonably delivers to the Fair Park Colleseum.

• Extremely low latency spans for use by the media production company. These spans support passing production video and audio between various points and must support an entry-to-exit latency not more than 1.1 milliseconds with a maximum allowable jitter of 100 microseconds.

• Interconnect with the Gizmo FMS network. The Gizmo FMS network must become a seamless part of the main event network to enable remote debugging from the production suite, as well as access to screens that exist solely within the Gizmo network's ecosystem at terminals not physically connected to the FMS network.

• Team connectivity. The fair park pavilion is old. There is no standing infrastructure and cellular service is spotty. As a result the event provides wifi to teams in the pit areas to enable access to debugging resources, online document suites, and other resources the team may need quick access to while in their pits.

• Remote access. At times it is necessary to provide a means of remote access to members of the BRI software development team to advise in the event of a non-nominal event occuring in some component of the BRI-managed software stack. This is usually facilitated by a screen sharing session, but can also be facilitated by a secure RDP session or SSH depending on the system in question and the preferences of the remote engineer being connected in.

• Host a myriad of internal applications. At a championship-scale event with an external media company, the network provides not only a large number of additional compositing resources, but file-shares for media assets and other resources. Running an HA pair of scoring servers requires additional infrastructure as well which must be hosted on-site.

• Quick deploy and un-deploy to avoid the total time we're in the space without access to the internet, as well as to support the various other systems and services that have to be deployed on top of the network.

This results in a few derived requirements:

• The network needs to be VLAN aware, and use sophisticated firewalls to protect the various security zones.

• The Gizmo FMS is capable of dynamic routing via BGP, so the event core must be able to act as a private BGP Peer.

• A robust application serving system must be available.

• The physical scale and unique power architecture of the fair park mandates the use of an optical core network.

This network is too large to fit in a single diagram, so we'll break it down into smaller parts:

In the production suite the equipment in the above diagram is connected to a large Uninteruptible Power Supply (UPS). This ensures that not only is the power on, but any dips or excursions in voltage are covered prior to reaching the compute equipment in the room.

The core router used, for reference, is a Mikrotik CCR2004-1G-12S+2XS. This is a 25Gbit/s capable core router with 12 10Gbit/s optical interfaces. Though there is no need to go as fast as 25Gbit/s, the important thing to consider is this router has sufficient memory to sustain enough NAT sessions to supply wifi to teams. The number of NAT sessions is estimated to be 15 per device across 350 devices to produce a pessimistic estimate. The core switch, similarly substantial, is an HPE 2350 PoE switch. This provides a good density of PoE enabled ports, while still supporting a fat-pipe architecture for its backplane.

The media switch is a ruggedized Netgear small office switch since it needs to actually sit with the production equipment. The access points used are Aruba Instant in a mix of 225 and 315 hardware, depending on deployed location.

Needless to say, all of this equipment is VLAN aware and supports policy based L3 routing and switching. This is a critical requirement to be able to keep various security zones isolated and to prioritize latency sensitive traffic. The VLANs in use are carefully coordinated against the Gizmo FMS pools to enable the Gizmo FMS router to make use of a layer 2 trunk for interconnection back to the core router.

The production suite maintains the core network, which feeds two smaller footprints on the main arena floor. The simpler of the two is in the pit area:

Connectivity in the pit area is characterized by 2 key use cases. For personal device connectivity, multiple access points are strategically deployed around the pits to ensure good connectivity and balance across the deployed radios. These access points require power to operate, which is supplied from the pit area switch via PoE.

The second connectivity provided to the pit area is in the form of computers that may be used to review scorecards. These computers are located at a designated table and have limited access to the scoring logistics VLAN since they need to be able to directly communicate with the game servers. Students may at any time recall a scorecard from these machines to review their progress or determine if a further inquiry is required.

The final area with concentrated network access is in the immediate game area. Most of this infrastructure is located at a row of tables set back from the fields where scorekeeping staff, production management, and key game personel sit.

The network footprint in the immediate game area is characterized by 3 key users. The simplest are wireless users roaming through the immediate area of the game field. These users transparently roam to the access point near the field, which is operating at 5Ghz to maintain band isolation against other equipment in the immediate field area. The access point is located physically with the field area switch, and is supplied with power via a PoE connection from the field area switch.

The second use case served at the field area is game scoring. This can be either score entry or score lookup (the scoring servers are back in the production suite). This is just a connection from some laptops to ports on the access switch that are connected to the scoring logistics VLAN. Its important to guard these ports and not provision this VLAN everywhere, so the game field area switch is really the only place that has several of these ports in a not-fully-consumed configuration. This is done as a choice to have more capacity than is required and avoid the need to adjust switch configs on-site.

The final consumer of network in the field area is the Gizmo FMS itself. This is, for clarity, the entire FMS and its associated functionality, but to simplify for this discussion, the FMS is considered to be the Scoring Table Box as that's the only point at which the two networks touch. Since the Scoring Table Box is a router in its own right, we have to use some additional techniques to interconnect it to the rest of the network. On Gizmo routers that have an SFP cage, the cage is configured as a switch trunk port with all the Gizmo's VLANs present on it. This means that we can just connect the SFP on the FMS router to a free SFP on the scoring area switch using a Direct Attach Cable (DAC) and with some careful planning the VLAN that allows the two routers to peer is present on the switch as one of the tagged VLANs. This peering is made using a BGP session, which allows the core router and the FMS router to dynamically exchange information about what traffic each one is responsible for.

This last part is getting into some fairly advanced networking, and most events won't ever need to care about it. We do this at Texas BEST to make it possible to treat both the Gizmo FMS and our existing event network as one large system without having to keep track of which network things are actually plugged in to. Security is maintained by a set of zone-based firewalls applied at the core router back at the production suite, which is the only place that its possible to hop from one security zone to another.

Streaming Your Event

Streaming your event can add an exciting new angle for participants who can't be present in the room. This expands the reach of BEST to grandparents, working parents, and other interested members of the public who are unable to physically attend.

Streaming your event is not hard, but does take some consideration.

Streaming Computers

Streaming your event requires at least one computer. A mini-PC like an HP EliteDesk is a good choice for this use case, and will provide a quick and easy way to get started. The computer will need at least one monitor though two displays makes it easier to see what you're doing.

Streaming Software

The software of choice for streaming is Open Broadcast Studio (OBS). OBS is a free program that composites various media sources such as cameras, static graphics, and live information feeds into a single video feed to be streamed out to external consumers such as YouTube, TwitchTV, and Facebook Live.

OBS has two screens, a configuration and management screen, and the multiview that shows you what every source is currently displaying.

Stream Encoders

To stream video from a camera to the internet, you will need to encode it into an appropriate format. This is almost always done by a computer, though it can be sepcialized hardware such as a BlackMagic Streaming Encoder. In either case, the encoder will be what defines the maximum resolution and frame-rate you can stream. An encoder in modern video systems will usually be integrated into a video switcher, though it need not be.

OBS

By far the most popular software available today for streaming is OBS. OBS (Open Broadcast Studio) is a free program that can ingest multiple video sources, composite them into a single program feed, and then export that to a myriad of different services for people to view the stream on.

OBS runs on macOS, Windows, and Linux, though my own usage is entirely restricted due to Linux due to the lower resource usage and better long-term stability. Both of these are factors to consider when running a stream that is consumed by a large number of people.

You can learn much, much more about OBS on the OBS website. The remainder of this section will focus on topics related directly to OBS as it pertains to BEST.

Scenes

OBS organizes different layouts into "scenes" which you can switch between at will. You can think of these as slides in a slide deck, but with the difference that you can transition from any slide to any other slide, not just those adjacent to the current slide.

A scene will always consist of at least one source, and may have multiple sources composited into a single scene to produce a layout that conveys a variety of dynamic and static information.

Video Sources

OBS supports many different types of video sources, but the most useful for our cases are the Media Source, Image Source, Browser Source, and Video Capture Source. Lets look closer at each one.

Media Source

The Media Source can, as the name implies, play most types of pre-recorded media. This is great for sponsor videos, game animations, or flashy "bumper" videos. The Media Source works best for audio and video resources.

Image Source

Like the Media Source, the Image Source works with images. This is great for loading logos and other graphics that you want to composite into the frame, or display as a standalone scene.

Browser Source

The Browser Source is perhaps one of OBS' most powerful sources. This source allows anything that can be loaded in a web-browser to be a source of content in a scene. This can include things you'd think of as a website, but also special purpose software that generates partial components that then get combined with other assets to produce a truly impressive and comprehensive video experience.

Video Capture Source

Depending on what operating system you deploy OBS on this source will be named slightly differently but the function is the same. This source will capture video from an external hardware device. This might be a camera or more specialized device such as a capture card.

Typical Arrangement

At a BEST event, there are usually 3 types of content that you'll want to present. The first and most obvious type is live video of your field. This can be captured using a camera or capture device that is connected to a camera indirectly. Usually having multiple angles of your field will improve the quality of your stream. Try to capture one top-down angle that shows the entire field from a bird's eye view, and then a lower angle with a long field of view.

The second common source will be static media assets. Things like hub logos, sponsor logos, and pre-recorded video. Care should be taken to ensure that the assets you use are of a high enough resolution to look good at the highest resolution you intend to stream. For most cases, if the media looks alright on a 1080p screen, all should be fine.

The final common source is comprised of various dynamic data sources that are pulled in as browser sources. These are things like scoreboards, schedules, and match clocks. Anything you can make a web page for can be displayed with the browser source after all.

Visually, this looks like this:

Computers

To stream any kind of content, you will need a computer to run your stream encoder on. In addition to the computer, you'll need a typical set of peripherals, such as monitors, keyboard and mouse, UPS battery backup (strongly recommended), and any other devices you want to use with the computer.

You can use a laptop to stream with, but unless you are using a fairly high performance laptop, or a portable workstation class machine, you will encounter issues with how much load video processing puts on the system. For these reasons, its recommended to use a system designed for desktop use. For very large events with an extremely large number of dynamic media sources, a full size desktop PC with powerful GPU is required. To get started, more modest hardware is perfectly acceptable.

Mini PCs

You can start streaming your events easily with modest mini-PC hardware. These are machines that occupy a market segment between laptops and small desktops. They usually use high-grade laptop components, but feature more peripherals and substantially better thermal design.

A great place to find these is on Amazon's renewed hardware listings. These listings feature the computer itself, a keyboard, mouse, and usually an assortment of Bluetooth and Wifi adapters.

The computers discussed below are ones I have personally used, and can vouch for.

Lenovo Thinkcentre m73 Tiny

Amazon Listing

This is a very small machine made by Lenovo. These can drive dual monitors, and feature discrete USB controllers which allows for using more USB webcams. While very inexpensive, these are older machines now, and will become outmoded as newer video codecs become available that are not supported by hardware.

HP Elitedesk 800

Amazon Listing

This is a higher spec machine than the Lenovo, and costs more as a result. It features still more USB controllers, and the DisplayPort supports multi-stream capability, which allows you to drive 3 monitors with an adapter like this one. With one display on VGA and additional displays on DP its possible to have a two monitor setup for controlling the system and additionally driving a projector locally with the same content that is going out to the internet.

Asus Expertcenter PN64-E1

Amazon Listing

This is a much more powerful machine, suitable for working at 4k resolution and featuring Intel QuickSync technology for hardware-assisted encoding. This means the machine can offload computationally intensive tasks to specialized hardware rather than running such tasks on the CPU. I pair this machine with addditional peripherals, and make use of its ability to drive two local displays for editing, and then casting out additional content to local projectors and venue video distribution hardware.

Raspberry Pi

You can run OBS on Linux, and in turn on a Raspberry Pi. This is a great way to maintain identical hardware everywhere if you're already using Raspberry Pi hardware for the Gizmo FMS.

Raspberry Pi 500

PiShop Listing

The Raspberry Pi 500 is an all-in-one style wedge-PC. This ARM based computer has sufficient power to run a respectable stream, but don't expect to be able to run more than 1-2 cameras and 1-2 browser sources. Static images and pre-recorded media are functionally free, so you can run as much of that as you want on any hardware.

Cameras

Usually you'll want to stream a live video feed in addition to any pre-recorded content. To do this, you'll need at least one camera. There are broadly two choices here, depending on whether you have a network or not. Cameras that connect directly to the streaming computer, and cameras that are accessed over the network.

Directly Connected Cameras

Directly connected cameras are, as the name implies, directly connected to the machine handling your stream. There are several choices here.

Most of these kinds of devices will attach using USB, and USB is an extremely strange standard if you look too closely. In general the following rules apply:

• Each camera will use about 200 MBit/s of bandwidth.
• Each USB controller can supply at most 480 MBit/s of bandwidth.
• There can be at most 7 USB Hubs in a chain, and hubs show up in far more places than you might expect (the cables below are technically 1 port hubs).

USB Webcams

The humble USB Webcam is a great choice for a first camera to stream with. More modern cameras made by Logitech feature the standard 1/4-20 tripod interface to enable mounting the camera on a tripod or grip, and since this is a standard thread, you can always just put a 1/4" 20 thread per inch bolt through some wood if you want to mount a camera directly to the field.

In particular, this one provides an impressive resolution, has the mounting hole, and features very good auto-focus. It does not like being on the end of a long cable though, so keep that in mind.

USB webcams can usually be extended by using USB extension cables, as long as the cable is an "active" cable. These cables usually have at least one "lump" in them, and are about 40' long. I have used these and found them to work pretty well. If plugged directly into a computer, or using a powered external hub, its possible to chain 2 of them together, though beware reliability issues when stacking USB cables in this fashion.

USB Capture Cards

USB Capture Cards allow you to ingest video from a source that doesn't plug in via USB, but instead uses some more specialized video connector. In my streaming systems, I currently use two different kinds of capture cards.

Magewell HDMI

Manufacturer Site

This is a dongle that shows up as a monitor to anything plugged into it. The video is then captured and converted into a pseudo-camera device that's presented to the computer on the USB side. I use several of these to allow ingesting presentations, powerpoints, and feeds from specialized media devices.

Magewell SDI

Manufacturer Site

SDI is a specialist format for passing around high-resolution broadcast video with audio embedded. This uses special cables, special adapters, and you start needing to understand a lot more video production concepts to use SDI. Where SDI is valuable is that many professional production companies work with it, and it is often the easiest compatible standard for a company to export the video from their systems to yours with.

Network Cameras

Network cameras are by and large a product of the security world. Networked surveilance cameras can be had quite inexpensively, and in the last few years have become extremely high resolution. I use Reolink RLC-510A cameras with an adapter base to fit them onto a tripod mount. These cameras are approximately 4k resolution, with a very slight fish-eye lensing. While I could remove the fish-eye lens, its also possible to remove the effect digitally since I'm re-framing the feed to 1080p. This downsampling makes the non-linear pixel density less of an issue.

Network cameras are a great choice if you already have a network since they usually will use Power Over Ethernet (PoE) meaning you only need one cable to carry signal and data. Ethernet cables can also be up to 300 feet, providing much more flexibility in placement for these cameras.