PCNE Cloud Interconnect Guide: Dedicated vs Partner (2026)

Deep dive into the hybrid connectivity area — the heaviest-weighted domain on the PCNE exam. We compare and operationalise Dedicated / Partner Interconnect, HA VPN, Cross-Cloud Interconnect, Network Connectivity Center, Private Service Connect, and Direct / Carrier Peering.

Connectivity Options at a Glance

Option	Bandwidth	SLA	Latency	Use case
Dedicated Interconnect	10G / 100G units	99.9% / 99.99%	Low	Enterprise / dedicated circuits
Partner Interconnect	50M〜50G	99.9% / 99.99%	Low to medium	Flexible bandwidth, regional sites
HA VPN	3 Gbps / tunnel	99.99%	Medium	Redundant cloud VPN
Classic VPN	3 Gbps / tunnel	99.9%	Medium	Legacy, not recommended for new
Cross-Cloud Interconnect	10G / 100G	99.9% / 99.99%	Low	AWS / Azure / OCI / Alibaba connectivity
Direct Peering	10G units	—	Low	Google services only
Carrier Peering	Carrier dependent	—	Medium	Google services only

Dedicated Interconnect in Detail

Facility: requires colocation in the same data center as a Google PoP (Point of Presence)
Capacity: 10 Gbps or 100 Gbps units
Redundancy: 99.9% SLA on a single circuit; 99.99% requires dual-metro redundancy
BGP: dynamic routing via Cloud Router
VLAN Attachment: logical split per VPC + region
Use case: multi-Gbps steady traffic and low-latency requirements

Partner Interconnect in Detail

How it works: connects to Google through certified carriers (NTT, KDDI, Equinix, Megaport, etc.)
Capacity: flexible bandwidth from 50 Mbps to 50 Gbps
SLA: 99.9% single connection, 99.99% redundant configuration
Use case: when there is no PoP in the same facility, or when smaller bandwidth is sufficient
Pricing: GCP charges VLAN Attachment + egress; the carrier charges separately

HA VPN in Detail

Topology: one pair of Cloud VPN Gateways (two external IPs) + an on-prem Peer VPN Gateway
Tunnels: typically 2 (active/active) for 99.99% SLA
BGP: required — dynamic routing via Cloud Router
Encryption: IKEv2 + IPSec
Throughput: 3 Gbps per tunnel; multiple tunnels can be aggregated
Pricing: tunnel-hour fee + egress data transfer fee

Cross-Cloud Interconnect (since 2023)

Direct connectivity to AWS / Azure / Oracle Cloud / Alibaba Cloud
10 Gbps / 100 Gbps, with 99.9% / 99.99% SLA
VPC networks communicate over private IPs
Use cases: multi-cloud DB replication, hybrid ML, data migration
Lower latency and reduced data transfer cost compared with traditional internet routing

Network Connectivity Center (NCC)

GCP's hub-and-spoke model
Hub: the central network
Spoke types: HA VPN, Interconnect VLAN, Router Appliance, Producer VPC
Use cases: global WAN consolidation, SD-WAN integration, multi-cloud aggregation
Data transfer charges apply

Private Google Access / Private Service Connect

Feature	Use case	Direction
Private Google Access (PGA)	VMs in a VPC → Google APIs / services	Egress
Private Google Access for on-prem	On-prem → Google APIs (via Interconnect)	Egress
Private Service Connect (PSC)	From a VPC → expose another tenant's / Google services as VPC IPs	Egress / Ingress
Private Service Access (PSA)	Connect to CloudSQL / Memorystore via VPC peering	Egress

Common Design Patterns

Enterprise hybrid: HA VPN (backup) + Partner Interconnect (primary)
Multi-cloud DB replication: Cross-Cloud Interconnect linking AWS Aurora ↔ Spanner
Global WAN: NCC hub + multi-region Interconnect spokes
SaaS delivery: expose your service into customer VPCs via PSC

When should I choose Dedicated vs Partner Interconnect?

Choose between dedicated 10 Gbps circuits (Dedicated) or flexible carrier-delivered bandwidth (Partner). Dedicated has strict same-facility requirements, so most enterprises end up using Partner Interconnect.

HA VPN or Classic VPN — which should I pick?

For new deployments, HA VPN is the only choice: 99.99% SLA, dual-tunnel redundancy, active/active. Classic VPN is single-tunnel with 99.9% SLA and is no longer recommended.

What is a VLAN Attachment?

A VLAN Attachment is the unit that logically splits an Interconnect circuit. Each attachment is bound to one VPC network and one region, so connecting multiple VPCs requires multiple VLAN attachments.

What does Cross-Cloud Interconnect enable?

Direct interconnection between GCP and AWS / Azure / Oracle Cloud / Alibaba Cloud. Lower latency and private-IP communication compared to going over the internet, plus reduced data transfer fees.

What is Network Connectivity Center (NCC)?

GCP's hub-and-spoke management platform. It centralises HA VPN, Interconnect, and Router Appliance into a single hub — the core building block for multi-site and multi-cloud designs.

What is the difference between Direct Peering and Carrier Peering?

Direct Peering uses BGP directly with Google; Carrier Peering goes via a carrier. Both reach only Google services (Gmail, Workspace, etc.) — they do not reach resources inside your VPC, which requires Interconnect.

What is the difference between Private Google Access and Private Service Connect?

Private Google Access lets VMs in a VPC reach Google APIs over private IPs. Private Service Connect exposes other tenants' or Google's services as endpoints inside your VPC.

What are the typical latency requirements asked about on PCNE?

Few-millisecond latency → Dedicated Interconnect; 10-50 ms → Partner Interconnect; best-effort → HA VPN. SLA ranges from 99.9% to 99.99% in that order.

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Google Cloud is a trademark of Google LLC. For the latest information, see the official Network Connectivity documentation.

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GCP PCNE Exam Guide: Cloud Interconnect, HA VPN, Cross-Cloud & NCC Deep Dive