Networks & transport reference

A wireless access point provides a Wi-Fi connection into a network. A home router often includes an access point, but the radio and routing roles are conceptually different. An additional access point can improve coverage when placed and connected appropriately.

Adaptive bitrate delivery lets a player choose among media versions supplied for a presentation. It can change versions as conditions or player decisions change, aiming to balance continuity and quality. The service must actually provide suitable alternatives for switching to occur.

Backhaul is the connection carrying traffic from an access point or mesh node toward the rest of the network. In a home mesh it can be wired or wireless. A strong player-to-node signal does not prove that this upstream connection is healthy.

Band steering is network behaviour intended to encourage compatible clients toward a suitable Wi-Fi band. The access point can influence the choice, but the client and its software also matter. A shared network name does not guarantee that every device always uses one particular band.

Bandwidth describes a connection's data-carrying capacity, commonly expressed in bits per second. It is a limit or available resource rather than a promise that every application will transfer at that rate. Several active devices can compete for the same connection.

Bitrate is the amount of encoded media data used per unit of time, often expressed in megabits per second for video. It describes data demand, not resolution by itself. Different encodes of the same-sized picture can use different bitrates.

A buffer underrun happens when the player runs out of usable media before enough new data is available. Playback may pause while the buffer refills. The immediate condition is empty media supply, but the underlying cause can lie in delivery, source availability or processing.

Cache-Control is an HTTP header used to express caching directives for a response or request. Correct behaviour depends on the resource and service design. Live playlists, static artwork and private account responses can have very different freshness and storage requirements.

A captive portal is a network access page that requires an action such as venue sign-in or accepting terms before ordinary internet access is granted. A player can join Wi-Fi successfully while remaining unable to reach its media server because this step is incomplete.

Carrier-grade NAT, commonly called CGNAT, is address translation operated within an access provider's network so multiple customers can share public addressing resources. It is distinct from the NAT performed by a home router. Customers may have limited control over it.

A content delivery network, or CDN, uses distributed infrastructure to deliver resources. It can reduce the distance or load involved in serving users, but a nearby endpoint is not a universal guarantee of smooth video. Routing, capacity and service configuration still matter.

Cross-Origin Resource Sharing, or CORS, is a browser mechanism governing whether script requests can use responses from another origin. The relevant server expresses permission through response headers. A resource can be online while unavailable to a particular webpage under that policy.

A DASH manifest, commonly called an MPD, describes a media presentation and its available components. A compatible player uses the information to request suitable audio and video resources. DASH is a delivery organisation, not the name of one universal codec.

The default gateway is the next network device a client normally uses to reach destinations outside its local subnet. In many homes this role belongs to the router. A player needs an appropriate gateway as part of its usable network configuration.

Dynamic Host Configuration Protocol supplies network configuration to clients, commonly including an IP address, subnet information, gateway and DNS servers. It lets ordinary home devices join without manually assigning every value. Wireless association and successful DHCP configuration are separate stages.

A DHCP lease assigns configuration to a client for a period managed by the DHCP system. Renewal allows a device to keep appropriate settings without treating the address as permanently owned. Lease duration is an administrative network choice, not a streaming-quality control.

A DHCP reservation tells the server to provide a consistent local address to an identified device. It combines predictable addressing with centrally managed configuration. It is different from purchasing a public static IP address from an internet provider.

A DNS cache stores previous resolution results for a period so repeated lookups need not start from scratch. It can improve efficiency, but a retained answer can temporarily differ from a recently changed service address. Caches exist at several different layers.

DNS over HTTPS, or DoH, carries DNS queries over an HTTPS connection to a compatible resolver. It protects that query path but is not a VPN and does not encrypt every application request. Its scope depends on the client and configuration.

DNS over TLS, or DoT, encrypts DNS communication using TLS between a compatible client and resolver. Like other encrypted-DNS methods, it protects a particular resolution path rather than all traffic from the device. It is separate from HTTPS media delivery.

A DNS resolver handles a client's name-resolution requests, obtaining or returning the relevant answer. Many home devices use the resolver supplied through network configuration, while some applications implement their own behaviour. Browser settings may not control every television app.

A DNS record's time to live, or TTL, indicates how long a cached answer can generally be retained before it needs refreshing under normal DNS behaviour. It helps balance caching and change propagation. It is not the subscription's remaining duration.

The Domain Name System, or DNS, helps translate names into information such as IP addresses. A player normally needs to resolve the server's hostname before connecting. A DNS problem can prevent access, but resolution is only one stage of the media workflow.

Double NAT describes traffic passing through two address-translating layers, such as a personal router behind a provider gateway. It can complicate inbound connectivity or some local arrangements, but ordinary outbound HTTP playback can still work. Its presence is not a universal buffering diagnosis.

Dual stack means a device or network supports both IPv4 and IPv6. Applications can use available addressing and connection mechanisms to reach destinations. The two paths need not have identical routing or performance, so their coexistence is useful context for diagnosis.

Duplex describes how communication directions are handled on a link. Full duplex permits simultaneous sending and receiving on a suitable Ethernet connection. A duplex mismatch can harm performance, but modern supported autonegotiation should not be replaced with random manual values.

Dynamic Frequency Selection, or DFS, is behaviour used on certain Wi-Fi channels to meet spectrum-sharing requirements, including radar detection. Equipment may need to move channels when required. Available channels and rules depend on the region and device.

Ethernet is a family of wired local-network technologies. For a stationary television, a supported Ethernet connection can remove wireless airtime and reception from that local hop. It does not eliminate limitations elsewhere between the device and the media source.

Autonegotiation is the process by which compatible Ethernet devices establish supported link characteristics. The resulting link rate is a local connection property, not a promise of equivalent internet throughput. Port capability and cabling influence the outcome.

A firewall applies rules to network traffic. It can operate on a device, router or managed network and may treat applications or destinations differently. A blocked request is one possible connection problem, but a generic playback pause does not prove a firewall caused it.

An HLS manifest is a playlist describing media resources and related presentation information for HTTP Live Streaming. A player can use it to select versions and request successive media pieces. Downloading the manifest successfully is only one stage of playback.

An HTTP redirect tells a client to use another URL for the relevant request. Browsers and players can differ in redirect handling, security policy and authentication behaviour. A marketing website's final address is not automatically the correct endpoint for a media-account field.

An HTTP status code describes the server's response to a particular request. It can indicate success, redirection, a client-related failure or a server-related failure. It does not necessarily describe the entire service or identify the precise account reason.

HTTPS is HTTP communicated over a secure connection using TLS in ordinary web operation. It protects that connection when validation succeeds. A secure hostname can still host misleading material, so HTTPS is not proof of an app's publisher, service legitimacy or content entitlement.

Internet Group Management Protocol, or IGMP, manages IPv4 multicast group membership between hosts and neighbouring routers. It is relevant to multicast operation, not a universal enhancement for every video app. Ordinary unicast HTTP viewing may not need IGMP-specific changes.

An IP address conflict occurs when devices on the same relevant network use an address that should be unique there. It can cause confusing reachability failures that appear intermittent as the competing devices become active. Similar address prefixes alone are not a conflict.

Fragmentation divides an IP packet into pieces to fit a smaller transmission limit where the protocol permits it. Behaviour differs between IPv4 and IPv6, and path-MTU mechanisms also matter. Fragmentation is not something a viewer should tune by guessing from a buffering spinner.

IPv4 is an Internet Protocol version that uses 32-bit addresses. Home networks commonly use private IPv4 addresses internally and translation toward internet access. An IPv4 address identifies network addressing, not a streaming account or a particular video quality.

IPv6 is an Internet Protocol version with a larger addressing space and its own network mechanisms. It can coexist with IPv4. Support alone does not guarantee a faster route, and one service failure does not establish that IPv6 should be disabled throughout the home.

Jitter concerns variation in the timing of arriving packets or measured delay. Even when average delivery looks adequate, uneven arrivals can challenge real-time applications. A media player uses buffered data to tolerate some of that variation before playback is affected.

Latency is the delay associated with data travelling through a system or network path. A common network measurement is round-trip time, which includes the journey out and back. That number is different from the total delay between a live event and its appearance on screen.

The live edge is the most recent part of a live presentation available to the player. It is not necessarily the real-world event occurring at that exact instant. Production, encoding and distribution have already introduced some delay before media becomes playable.

Maximum Transmission Unit, or MTU, is the largest packet size supported on a particular link without fragmentation at that layer. Different network arrangements and tunnels can impose different requirements. It is not a general video-quality setting.

A media segment is a piece of a presentation requested as part of segmented delivery. Successive pieces let a player continue a programme as data becomes available. Segment duration and publication timing contribute to buffering and live delay, alongside other stages.

Mesh Wi-Fi uses coordinated nodes to extend wireless coverage across a space. The system can simplify management, but its performance still depends on placement, backhaul and client behaviour. Adding nodes does not automatically increase the internet service's capacity.

Mixed content occurs when a secure context tries to use an insecure resource. Browsers restrict such combinations to protect the user. A secure video page can therefore load its interface while failing to play media from an unsuitable insecure address.

Multicast delivers traffic to a group of interested recipients within a network arrangement that supports it. Some managed television systems use multicast, but the word IPTV does not prove that a particular internet player does. Delivery models need to be verified.

Network Address Translation, or NAT, changes address information as traffic crosses a network boundary. In a typical home setup it allows private-addressed devices to use the internet connection. NAT behaviour is separate from a streaming account's permitted number of screens.

An origin server is the source system from which delivery infrastructure obtains a resource. A CDN edge or gateway may be reachable while the origin or another backend fails. A website responding does not prove that every media source behind it is healthy.

Packet loss occurs when expected packets do not arrive at their destination or are not observed by a particular measurement. Its effect depends on the transport and application: recovery, buffering or error concealment may hide some loss, while repeated disruption can harm playback.

A playback buffer holds media received ahead of the moment it is shown. It gives the player a cushion against short delivery gaps. A larger cushion can improve continuity, but a live programme will normally be farther behind its source.

Port forwarding directs selected incoming traffic from a router toward a local service. It is commonly used for deliberately hosted applications. Most ordinary video players request remote media outbound and do not need arbitrary incoming ports opened for viewing.

A proxy handles supported requests on behalf of a client. Applications may use a system proxy, their own proxy configuration or neither. A stale proxy setting can therefore affect one app differently from another on the same computer or network.

QUIC is a transport protocol built over UDP, with multiplexed streams and integrated security mechanisms. HTTP/3 uses QUIC, but QUIC itself is not a video codec. Whether a viewing session uses it depends on the client, server and network.

Received Signal Strength Indicator, or RSSI, represents a device's observation of received radio strength. How it is exposed and scaled can vary between equipment. It is one useful local measurement, not a complete assessment of Wi-Fi quality or internet performance.

Signal-to-noise ratio compares the desired radio signal with the surrounding noise level. It adds context that signal strength alone cannot provide. A useful Wi-Fi connection depends on receiving the intended transmission clearly enough amid the actual radio environment.

A signed URL includes information the service uses to authorise a particular request, often with an expiry. It can grant temporary media access without being a permanent catalogue address. The exact scheme and validation rules belong to the service.

An SSID is the name used to identify a Wi-Fi network to clients. It is not the network password and does not establish that every device seeing the name can communicate with every other device. Router policy still determines access.

A subnet is a logical portion of an IP network defined by its addressing and prefix or mask. Devices use this information to decide whether a destination is local or needs a gateway. Similar-looking addresses do not by themselves prove two devices can communicate.

Throughput is the rate at which data actually passes through a measured path during a particular interval. It can be lower than the advertised connection capacity because of overhead, competing traffic, radio conditions and limits elsewhere in the path.

Transmission Control Protocol, or TCP, provides an ordered reliable byte stream between endpoints. It includes mechanisms for handling lost data and controlling transmission. Reliable delivery does not mean every recovered byte arrives before a video player's playback deadline.

Transport Layer Security, or TLS, protects communication between compatible endpoints through cryptographic mechanisms including confidentiality and integrity. Certificate validation helps the client establish trust in the named endpoint. It does not certify the business's content rights or every claim on its website.

Unicast sends data from one sender toward one recipient in the relevant communication model. In ordinary internet media delivery, each active player commonly receives its own stream. Several screens showing the same programme can therefore add to household data demand.

Universal Plug and Play is a family of technologies used for device discovery and related network functions. Some router implementations permit applications to request port mappings. That capability is different from ordinary outbound media requests and is not universally required for streaming.

User Datagram Protocol, or UDP, transports datagrams without itself providing TCP-style ordered reliable delivery. Applications using UDP determine how to handle timing, missing data and other requirements. Some higher-level protocols add substantial recovery and security mechanisms of their own.

Airtime is the time occupied by transmissions on a wireless channel. Devices sharing radio space must take turns according to Wi-Fi operation, so a high advertised radio rate does not mean each client receives that rate continuously. Busy neighbours and household devices can affect the available opportunity.

Channel width describes how much radio spectrum a Wi-Fi channel uses. Wider configurations can offer more capacity under suitable conditions, but also occupy more spectrum. The widest available choice is not automatically the most reliable in every building or band.

Wi-Fi Multimedia, often abbreviated WMM, provides traffic-handling categories within Wi-Fi operation. It is not the same as the internet provider's capacity or every router feature labelled QoS. Follow the access point's recommended configuration rather than disabling it as a generic tuning trick.

A Wi-Fi repeater extends coverage by receiving and retransmitting wireless traffic. Its useful performance depends on both its connection to the router and its connection to the client. Strong signal from the repeater does not guarantee a strong end-to-end path.

Wi-Fi roaming is the process of a client moving between access points that provide network access. It is especially relevant when a phone or tablet moves through a building. The client, coverage and network features all influence how smoothly the change happens.