# Glossary This glossary defines the terms [Connectors](/en/documentation/platform/connectors/) uses in its own way, together with the terms of [Load Balancer](/en/documentation/platform/connectors/#load-balancer), [Origin Shield](/en/documentation/platform/connectors/#origin-shield), and [Live Ingest](/en/documentation/platform/connectors/#live-ingest), which work on a connector. | Term | Definition | | ------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | address | The IPv4 address, IPv6 address, or hostname of a server that a connector of type `http` connects to, written with no protocol and no port. A connector holds one address, or up to 15 with Load Balancer on, and each address carries its own `http_port` and `https_port`. An address is also called an endpoint, and [Connector settings](/en/documentation/platform/connectors/settings/#addresses) lists every address field. | | Azion Origin Shield list | The [network list](/en/documentation/platform/firewall/network-shield/network-lists/) named `Azion Origin Shield`, which holds the IPv4 and IPv6 prefixes of Azion's network infrastructure. Your origin's firewall uses it as an allowlist that accepts inbound traffic from these addresses only, and you automate updates to that allowlist as the list changes. For the steps, refer to [Allow Azion's IP ranges at your origin](/en/documentation/support/retrieve-azion-ip-ranges/). | | balancing method | The rule Load Balancer follows to choose an address for each request, also called a steering policy. **Method** in Azion Console and `method` in the API take *Round Robin* (`round_robin`, the default), *Least Connections* (`least_conn`), or *IP Hash* (`ip_hash`). Each data center balances on its own, so the split is never exact, and [Balancing methods](/en/documentation/platform/connectors/load-balancer/balancing-methods/) describes how each method chooses. | | connector | The object that holds where and how an application reaches an [origin](https://www.azion.com/en/learning/), the server that holds your content, also called a backend. Several applications can reuse one connector, and each sends requests to it through a rule with the `Set Connector` behavior. The API serves connectors at `/v4/workspace/connectors`, [Connectors](/en/documentation/platform/connectors/) describes the resource, and the [Connectors quickstart](/en/documentation/platform/connectors/quickstart/) creates one. | | connector type | The `type` of a connector: `http` for origin servers, `storage` for an Object Storage bucket, or `live_ingest` for live video ingestion. Azion Console offers it as the **Connector Type** cards *HTTP*, *Object Storage*, and *Live Ingest*, and the type sets which fields `attributes` takes. [Connector settings](/en/documentation/platform/connectors/settings/#general) lists the fields of each type. | | DNS resolution policy | The option that sets which IP version a connector of type `http` uses to reach its addresses: **DNS Resolution Policy** in Azion Console, `dns_resolution` in the API. `both`, the default and *IPv4 and IPv6* in Azion Console, connects over either version, and `force_ipv4`, *Force IPv4*, connects over IPv4 only. [Connector settings](/en/documentation/platform/connectors/settings/#connection-options) documents it with the other connection options. | | HMAC | The [hash-based message authentication](https://www.azion.com/en/learning/) that Origin Shield adds to every request to the origin, so a private S3-compatible bucket can serve it. It uses `aws4_hmac_sha256` and one set of credentials from your object storage provider, **Region**, **Service**, **Access Key**, and **Secret Key**, for every address. [Sign origin requests with HMAC](/en/documentation/guides/application-development/getting-started/sign-origin-requests-with-hmac/) sets it up, and turning it off removes the stored credentials. | | Host header | The `Host` header a connector of type `http` sends to the origin, which the origin reads to select the [virtual host](https://www.azion.com/en/learning/) that serves the content. **Host** in Azion Console and `host` in the API default to `${host}`, which sends the host the client requested, and a literal value is sent as is. [Set the Host header and path prefix for an origin](/en/documentation/guides/application-development/getting-started/set-the-host-header-and-path-prefix/) shows when to send the origin's own name. | | ingestion region | The region where a connector of type `live_ingest` ingests a live video stream: **Region** in Azion Console, `attributes.region` in the API. It is required and takes `us-east-1`, `us-east-2`, `br-east-1`, `br-east-2`, or `br-east-3`, so choose the one that minimizes latency for your stream. [Connector settings](/en/documentation/platform/connectors/settings/#live-ingest) lists the errors a missing or unknown region returns. | | Live Ingest | The ingestion of live video streams through a connector of type `live_ingest`, in the ingestion region you select. It is billed on Data Ingestion, measured per GB. [Live Ingest](/en/documentation/platform/connectors/#live-ingest) describes it, and [Ingestion and delivery](/en/documentation/platform/connectors/live-ingest/ingestion-and-delivery/) explains how it works. | | Load Balancer | [Load balancing](https://www.azion.com/en/learning/) across the addresses of one connector of type `http`, also called a pool. Enabling Load Balancer on the connector, with the **Load Balancer** switch or `attributes.modules.load_balancer.enabled`, raises the address limit from 1 to 15. [Load Balancer](/en/documentation/platform/connectors/#load-balancer) describes it, and the [Load Balancer quickstart](/en/documentation/platform/connectors/load-balancer/quickstart/) balances a first connector. | | Origin IP ACL | The switch inside Origin Shield, **Origin IP ACL** in Azion Console and `attributes.modules.origin_shield.config.origin_ip_acl.enabled` in the API, off by default. It lets your origin accept only Azion's published addresses, the Azion Origin Shield list, by allowing them in the origin's firewall. [Origin IP ACL and HMAC](/en/documentation/platform/connectors/origin-shield/origin-ip-acl-and-hmac/) explains the mechanism. | | Origin Shield | The protection of the origin of a connector of type `http` by two controls: Origin IP ACL, an allowlist of Azion's addresses, and HMAC request signing. You enable [Origin Shield](/en/documentation/platform/connectors/#origin-shield) on the connector with the **Origin Shield** switch or `attributes.modules.origin_shield.enabled`, and it is billed on Shielded Connectors. A cache layer between Azion's cache and the origin, sometimes also called an origin shield, is [Tiered Cache](/en/documentation/platform/applications/cache/tiered-cache/). | | path prefix | The path a connector of type `http` puts in front of the requested path: **Path** in Azion Console, `path_prefix` in the API. It starts with `/` and is empty by default, and with `/anything`, a request for `/get` reaches the origin as `/anything/get`. [Connector settings](/en/documentation/platform/connectors/settings/#connection-options) lists its bounds and errors. | | real IP header | The header that carries the client IP address to the origin, `X-Real-IP` by default, named in **Real IP Header** in Azion Console or `real_ip_header` in the API. Renaming it changes the header the origin receives, and **Real Port Header**, `real_port_header`, carries the client port in `X-Real-PORT`. To add the client IP with a rule instead, refer to [Send the client IP to the origin in a header](/en/documentation/support/original-ip-header/). | | server role | The role of an address when Load Balancer is on, **Server Role** in Azion Console and `server_role` in the API: *Primary* (`primary`, the default) or *Backup* (`backup`). A backup address stands by and receives requests only when every primary address fails. The *IP Hash* method refuses backup addresses with `28005`, and [Balancing methods](/en/documentation/platform/connectors/load-balancer/balancing-methods/) describes how the role changes the choice. | | Set Connector | The behavior, *Set Connector* in Azion Console and `set_connector` in the API, that sends the requests an application rule matches to one connector. The rule names the connector by its ID in `attributes.value`, and when several matching rules carry the behavior, only the last one runs. Until a rule names a connector, an application has no origin, and [Rules Engine for Applications](/en/documentation/platform/applications/rules-engine/) documents the behavior. | | Single Origin | The name the plans give to a connector with one address, which Hobby, Pro, and Enterprise each include. It is also the Origin Type of a v3 origin with one address, documented in [Origins](/en/documentation/platform/connectors/origins/). A connector with more than one address uses Load Balancer, as [Connectors limits](/en/documentation/platform/connectors/limits/#connectors) shows. | | transport protocol policy | The option that sets the protocol a connector of type `http` uses to reach its addresses: **Transport Protocol Policy** in Azion Console, `transport_policy` in the API. *Preserve* (`preserve`, the default) keeps the scheme the client used, *Force HTTPS* (`force_https`) connects over HTTPS only, and *Force HTTP* (`force_http`) over HTTP only. [Connector settings](/en/documentation/platform/connectors/settings/#connection-options) documents it with the other connection options. | | weight | A number from 1 to 100 that sets the share of requests an address receives when Load Balancer is on, `1` by default. Higher weights allocate more traffic to an address, set in **Weight** in Azion Console or `weight` in the API. [Balancing methods](/en/documentation/platform/connectors/load-balancer/balancing-methods/) describes how weight changes the choice. |