Nokia Services Architecture key terms

A passive optical access technology that uses one fibre from the exchange split by unpowered splitters to serve many homes, with downstream traffic broadcast and upstream traffic time-slotted.

A symmetric 10 Gbit/s passive optical access standard, typically coexisting with older GPON on the same fibre plant through wavelength coexistence filters, used for higher-bandwidth residential and business services.

The optical line terminal is the access node at the network end of a PON. It schedules upstream grants, manages ONTs, and uplinks traffic toward the aggregation and core.

The optical network terminal is the subscriber-side PON device that terminates the fibre, converts to electrical interfaces for the home or business, and is provisioned and managed by the OLT.

Delivering broadband to a premises over a radio link instead of fibre or copper, using customer premises equipment aimed at a base station; a fast way to serve areas without fixed-line infrastructure.

The New Radio air interface for 5G, supporting flexible subcarrier spacing, wide bandwidths in sub-6 GHz and millimetre wave, and both standalone and non-standalone deployment options.

A 5G deployment where the radio connects to an existing 4G core for control plane anchoring, with 5G carriers added for capacity; faster to launch but lacks full 5G core capabilities.

Control and user plane separation splits the control functions of a gateway from its packet-forwarding role, so each can scale independently and user plane can be placed close to users.

The access and mobility management function is the 5G core element handling registration, connection and mobility management and NAS signalling, while user data bypasses it.

The session management function creates, modifies and releases PDU sessions in the 5G core, selects the user plane function, and allocates IP addresses to devices.

The user plane function forwards and routes user packets in the 5G core, applies policy and charging enforcement, and can be deployed centrally or near the edge.

Partitioning one physical network into isolated logical networks, each with its own resources, topology and service guarantees, so diverse use cases do not degrade each other.

The lifecycle process of designing, instantiating, monitoring and retiring network slices, mapping service requirements to subnets and resources across access, transport and core.

Optical transport network wraps client signals in fixed-rate containers with strong forward error correction and operations overhead, enabling transparent, manageable wavelength transport in the metro and backbone.

Dense wavelength division multiplexing carries many independent optical channels on one fibre at closely spaced wavelengths, multiplying capacity without new fibre and feeding optical add-drop nodes.

A reconfigurable optical add-drop multiplexer switches wavelengths between fibre spans without electrical conversion, allowing remote provisioning of lightpaths and flexible restoration at optical nodes.

A source-based routing method where the ingress node lists a sequence of segment identifiers in the packet header, steering traffic through chosen paths without per-hop state in the core.

Segment routing applied to IPv6, encoding the segment list in an IPv6 routing header so paths can be programmed end to end and combined with network programming behaviours at each node.

Multiprotocol label switching forwards packets using short fixed-length labels rather than full IP lookups, supporting traffic engineering, virtual private networks and fast reroute in service provider cores.

A service where a provider carries customer IP routes across its backbone using virtual routing instances, so separate customers can use overlapping addresses with controlled reachability between sites.

Ethernet VPN uses BGP control-plane signalling to distribute MAC and IP reachability for layer 2 and layer 3 services, improving convergence and multihoming over older flood-and-learn designs.

An overlay encapsulation that carries layer 2 frames inside UDP/IP packets using a 24-bit segment identifier, allowing large numbers of isolated virtual networks across a routed underlay.

A data centre fabric topology where every leaf switch connects to every spine, giving predictable low latency and even bandwidth between servers; traffic between leaves crosses one spine hop.

The ratio between capacity available to servers and capacity toward the spine, a design choice that trades cost against the likelihood of congestion for east-west traffic in the fabric.

Using point-to-point radio links, typically 6 to 80 GHz, to carry mobile site traffic to the network where fibre is unavailable or too slow to deploy, with capacity set by bandwidth and modulation.

A radio link feature that changes modulation and coding with channel conditions, dropping to robust low-order schemes in fading and raising them in clear conditions to protect availability.

The extra received signal power designed above the minimum required, covering rain, multipath and atmospheric fading so a microwave link meets its availability target over the year.

Automatically bringing a new network device into service, discovering it, loading the right software and configuration and validating it, without manual on-site configuration by an engineer.

An approach where operators declare the desired outcome, such as reachability or latency, and the system translates it into configuration, verifies it and corrects drift automatically.

Automation that continuously observes network state, compares it with the target, and takes corrective action without human intervention, with the loop repeating as conditions change.

Streaming fine-grained operational data from network devices at short intervals, rather than polling counters, so analytics and automation see near-real-time state for assurance and control.

A continuously updated virtual model of a network built from live data, used to simulate changes, predict effects and test automation before applying it to the real infrastructure.

A defined programmatic interface exposing network capabilities, such as quality on demand or device location, to application developers, typically with authentication, quotas and service-level terms.

An open project defining common, operator-agnostic API specifications for telco capabilities so developers can use the same interface across many networks and countries.

The 5G core element that securely exposes network capabilities and events to external applications through APIs, hiding internal topology and applying authorisation and policy.

Secure access service edge combines network connectivity such as SD-WAN with cloud-delivered security functions, applying policy close to users and devices wherever they connect.

A security model that grants no implicit trust based on network location, verifying identity and device posture for every access request and enforcing least privilege continuously.

Dividing a network or data centre into fine-grained zones with explicit allow rules between workloads, limiting lateral movement if one host is compromised.

Software-defined wide area networking centrally manages links of mixed types, steering application traffic over the best path and applying policy, often paired with cloud security services.