Glossary

Definitions of technical and product terms used across this documentation. Most terms link to the pages where they appear in context.

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Definitions of technical and product terms used across this documentation. Most terms link to the pages where they appear in context.

A

Active-Active - A redundancy pattern where two connections carry production traffic simultaneously, with path preference controlled by BGP attributes such as local preference and AS-PATH.

Active-Passive - A redundancy pattern where one connection carries production traffic while a second standby connection takes over on failure. Switchover is usually triggered by BGP session loss or BFD.

ASN (Autonomous System Number) - A globally unique number assigned to a network for use with BGP. Each side of a BGP session declares its ASN. Tata Communications uses ASN 4755 on the GVPN side of IZO™+ Multi Cloud Connect connections.

AWS Direct Connect - Amazon’s service for establishing a dedicated network connection between an on-premises network and AWS. IZO™+ Multi Cloud Connect delivers Direct Connect as a managed service via Hosted Connections.

Azure ExpressRoute - Microsoft’s service for extending on-premises networks into Azure over a private connection. IZO™+ Multi Cloud Connect delivers ExpressRoute as a managed service.

Bandwidth slab - A specific bandwidth tier offered for an IZO™+ Multi Cloud Connect connection. Slabs are cloud-provider-specific; for example, AWS supports 50 Mbps to 25 Gbps and Azure supports 50 Mbps to 10 Gbps.

BFD (Bidirectional Forwarding Detection) - A protocol for sub-second detection of link failures, paired with BGP to accelerate failover between redundant connections.

BGP (Border Gateway Protocol) - The dynamic routing protocol used between a customer network and a cloud provider over IZO™+ Multi Cloud Connect. BGP advertises prefixes, controls path selection, and enables fast failover.

Class of Service (COS) - A QoS marking used to prioritise traffic on the Tata Communications MPLS backbone. IZO™+ Multi Cloud Connect connections are typically configured with a single COS class to provide consistent quality of service.

Cloud-to-Cloud Connectivity - A deployment pattern where two or more public clouds are interconnected privately through IZO™+ Multi Cloud Connect, eliminating the public-internet path between them.

CPE (Customer Premise Equipment) - The customer-side network device (typically a router) that terminates the IZO™+ Multi Cloud Connect connection at the enterprise site. CPE can be managed by Tata Communications or by the customer.

Deployment scenario - The topology in which IZO™+ Multi Cloud Connect is deployed at the customer side. The four supported scenarios are Full Mesh, Hub-and-Spoke, Cloud-to-Cloud, and Selected Site.

DRG (Dynamic Routing Gateway) - Oracle Cloud Infrastructure’s edge routing component, attached to FastConnect connections to exchange routes with the customer network.

ExpressRoute Direct - A high-capacity variant of Azure ExpressRoute offering port pairs at 10 or 100 Gbps. Customers requiring sustained multi-gigabit throughput choose ExpressRoute Direct over standard ExpressRoute.

FastConnect - Oracle Cloud Infrastructure’s private connectivity service. IZO™+ Multi Cloud Connect delivers FastConnect as a managed service.

Full Mesh Topology - A deployment where every customer site can reach every other site directly through the GVPN backbone, with no central hub.

GSTIN (Goods and Services Tax Identification Number) - The Indian tax registration identifier collected during TCx Portal sign-up for customers in India. Required for billing and invoicing.

GVPN (Global Virtual Private Network) - Tata Communications’ MPLS backbone. IZO™+ Multi Cloud Connect services are delivered over GVPN.

High Availability (HA) - A design pattern in which redundant components ensure service continuity in the event of a failure. For IZO™+ Multi Cloud Connect, HA typically means two physical connections to a cloud provider, with BGP managing failover.

Hosted Connection - A logically partitioned AWS Direct Connect connection delivered over a Tata Communications-managed or Equinix-routed interconnect. Supports a single VLAN per connection and bandwidths from 50 Mbps to 25 Gbps.

Hub-and-Spoke Topology - A deployment where a central hub site brokers connectivity for a set of remote spoke sites. All spoke-to-cloud and spoke-to-spoke traffic transits the hub.

IPsec (Internet Protocol Security) - A protocol suite for encrypting and authenticating IP packets. Used in IZO™+ Multi Cloud Connect when an enterprise site connects over the public internet rather than MPLS, encrypting the underlay link.

IZO™ - Tata Communications’ family of cloud-connectivity products. IZO™+ Multi Cloud Connect (MCC) is one member of the family.

IZO™+ MCC - Tata Communications’ private cloud connectivity service that links enterprise networks to AWS, Azure, GCP, Oracle, and IBM Cloud through dedicated interconnects.

IZO™+ MCC Flex - The NFV-based variant of IZO™+ Multi Cloud Connect that delivers connectivity through virtualised network functions (router, firewall, SD-WAN) rather than physical interconnects.

IZO™+ MCC Secure - The variant of IZO™+ Multi Cloud Connect that integrates Firewall-as-a-Service for end-to-end inspection of cloud-bound traffic.

KYC (Know Your Customer) - The identity-verification step in the TCx Portal sign-up flow, where the customer’s legal entity, GSTIN, and address are validated before billing can begin.

Legal Entity - The registered business name under which the customer subscribes to IZO™+ Multi Cloud Connect. Collected during sign-up and used on all contracts and invoices.

Looped Interface - The architectural pattern in the IZO™+ Multi Cloud Connect modular design where a single GVPN PE router has an internal loopback connection: one end terminates the GVPN service VPN, the other end terminates the cloud Virtual Circuit. This allows the two layers to be provisioned independently.

MACsec - IEEE 802.1AE Layer-2 encryption protocol, available on supported AWS Direct Connect configurations for line-rate encryption between the customer port and AWS.

MPLS (Multiprotocol Label Switching) - The packet-forwarding technology that underpins Tata Communications’ GVPN backbone. Provides traffic engineering, QoS, and VPN isolation.

MRC / NRC (Monthly Recurring Charge / Non-Recurring Charge) - The two pricing components for IZO™+ Multi Cloud Connect. MRC is the ongoing monthly fee for bandwidth; NRC is the one-time setup charge.

MSEE (Microsoft Enterprise Edge) - Microsoft’s edge routers used to terminate Azure ExpressRoute circuits. IZO™+ Multi Cloud Connect peers with two MSEE routers per ExpressRoute circuit for redundancy.

MTU (Maximum Transmission Unit) - The largest packet size supported on a network link. Standard MTU is 1500 bytes; jumbo MTU (typically 9000 bytes) is supported on some IZO™+ Multi Cloud Connect interconnects to improve throughput.

NFV (Network Function Virtualization) - The practice of running network functions (routing, firewalling, SD-WAN) as virtual machines on commodity hardware rather than dedicated appliances. IZO™+ Multi Cloud Connect Flex is built on NFV principles.

NGE (Next Generation Encryption) - A modern suite of cryptographic algorithms supported on IZO™+ Multi Cloud Connect Service Gateway routers for customers using IPsec underlays.

OTP (One-Time Password) - A short, time-limited code sent to the customer during TCx Portal sign-up to verify their email address and mobile number.

PE Router (Provider Edge Router) - A router on the edge of the Tata Communications MPLS backbone that terminates customer connections. IZO™+ Multi Cloud Connect services are provisioned on GVPN PE routers.

PoP (Point of Presence) - A physical location where Tata Communications operates network infrastructure. Each PoP is a potential entry point to the GVPN backbone.

Private Peering - The Azure ExpressRoute peering type used to reach private Azure resources in customer VNets. Distinct from Microsoft Peering, which reaches public Azure services.

Public Peering - The AWS Direct Connect peering type used to reach public AWS services (EC2, S3, DynamoDB, etc.) over the dedicated connection rather than the public internet.

QinQ (802.1ad) - A VLAN-stacking technique where one VLAN tag is encapsulated inside another. Used between Tata Communications GVPN PE routers and AWS Direct Connect interconnects to manage customer VLANs at scale.

Selected Site - A deployment scenario where only specific enterprise sites are connected to a given cloud, useful for staged migrations and limited-scope production cutovers.

Service Gateway - A Tata Communications router that provides Extended Access Services, allowing internet-connected customer sites to reach IZO™+ Multi Cloud Connect services over IPsec.

Service Type - The product category selected in the TCx Portal when raising a service request or browsing inventory. Examples: GVPN, IAS, IZO SDWAN, IZO™+ Multi Cloud Connect Direct.

SLA (Service Level Agreement) - The contractual guarantees Tata Communications provides on availability, latency, packet loss, and jitter for IZO™+ Multi Cloud Connect services.

TC^x Portal - Tata Communications’ self-serve customer portal. Used for placing orders, viewing inventory, raising service requests, and monitoring connections.

Transit VIF (Transit Virtual Interface) - An AWS Direct Connect virtual interface attached to a Transit Gateway, providing access to multiple VPCs across multiple AWS regions over a single connection.

VIF (Virtual Interface) - The BGP peering session over an AWS Direct Connect connection. Three types: Private VIF (VPC access), Public VIF (AWS public services), and Transit VIF (multi-region via Transit Gateway).

VLAN (Virtual LAN) - An 802.1Q tag used to logically separate traffic over a shared physical link. Each IZO™+ Multi Cloud Connect Hosted Connection uses one VLAN.

VNF (Virtualized Network Function) - A network function (router, firewall, SD-WAN) implemented in software and deployed within IZO™+ Multi Cloud Connect Flex.

VPC (Virtual Private Cloud) - An isolated virtual network in a cloud provider’s infrastructure. Customers configure their on-premises network to reach one or more VPCs over IZO™+ Multi Cloud Connect.

VRF (Virtual Routing and Forwarding) - A routing-table partition on a single router that isolates one customer’s traffic from another’s. Used throughout the Tata Communications GVPN backbone.