What Is IP Transit?
IP transit is a paid network service that provides a network with access to destinations across the Internet through an upstream provider.
In simple terms, IP transit gives a network a path to the broader Internet. The customer connects to a transit provider and typically uses BGP to exchange routing information. The provider then carries traffic to networks that are not directly reachable through the customer’s own infrastructure or peering relationships.
IP transit is commonly used by ISPs, hosting and data center providers, cloud platforms, enterprises with their own networks, and other organizations that need broad Internet connectivity.
Key Takeaways
- IP transit provides access to destinations across the broader Internet through an upstream network.
- BGP is typically used to exchange routing information between the customer and transit provider.
- Peering provides direct traffic exchange between networks, while transit provides broader Internet reachability.
- Multiple transit providers can provide redundancy and routing diversity.
- Transit performance depends on carrier selection, routing, geography, congestion, and peering – not just bandwidth.
How Does IP Transit Work?
IP transit operates between independent networks, usually represented by Autonomous Systems (AS). Each AS has an Autonomous System Number (ASN), and BGP is used to exchange information about which IP networks can be reached.
A typical IP transit setup works like this:
- The customer connects to the provider – The network establishes a physical or logical connection to the transit provider.
- BGP is established – The customer and provider exchange routing information.
- Customer prefixes are advertised – The customer announces the IP networks it originates.
- Internet routes are received – The customer receives routes from the transit provider, which may include a full routing table or a default route depending on the setup.
- Traffic is forwarded – Traffic destined for external networks is sent through the transit provider when a more specific direct or peering route is unavailable.
Networks using multiple upstream providers can use BGP policies to influence path selection, provide redundancy, and manage traffic across available connections.
XLC operates a BGP4 multihomed network combining Tier 1 transit, direct China carrier connectivity, Internet Exchange peering, and private cloud interconnects.
IP Transit vs Peering: What Is the Difference?
IP transit and peering are different types of network interconnection.
With IP transit, a network pays a provider to carry traffic to destinations beyond its own network and direct relationships.
With peering, two networks exchange traffic directly between each other. Peering can take place privately or through an Internet Exchange Point (IXP).
| Characteristic | IP Transit | Peering |
|---|---|---|
| Main purpose | Broad Internet reachability | Direct traffic exchange |
| Relationship | Customer and provider | Network-to-network |
| Routing scope | Broad set of Internet destinations | Specific connected networks and their routes |
| Payment | Paid service | May be settlement-free or commercial |
| Typical use | Internet access and global reach | Direct paths and reduced transit dependence |
The two are often used together. A network can use peering for traffic destined for connected networks and IP transit for destinations that are not directly reachable.
What Is Tier 1 IP Transit?
A Tier 1 network is generally a network that can reach the entire Internet without purchasing transit from another network. It relies on its own customers and peering relationships to maintain global reachability.
The term Tier 1 describes a network’s position and commercial relationships within the Internet ecosystem. It is not a separate routing protocol or technical standard.
For a transit customer, access to major Tier 1 carriers can provide extensive network reach and multiple international paths. However, the Tier 1 label alone does not guarantee the best performance. Carrier diversity, routing policies, peering, geography, congestion, and regional connectivity also matter.
XLC’s current network architecture combines multiple Tier 1 and regional carriers with direct connectivity to China and APAC Internet Exchange peering.
Why Do Networks Use Multiple Transit Providers?
Using more than one IP transit provider is known as multihoming.
Multihoming can provide:
- Redundancy – another upstream can remain available if one connection fails.
- Route diversity – different providers may offer different paths to the same destination.
- Traffic engineering – BGP policies can influence preferred routes.
- Regional optimization – a provider may have stronger connectivity to a particular market.
- Reduced dependence on one upstream – traffic does not have to rely on a single carrier.
Multiple providers do not automatically make a network faster. The benefit depends on whether the available networks provide genuinely useful route diversity and connectivity for the traffic being carried.
What Role Does BGP Play in IP Transit?
BGP is the routing protocol that allows independent networks to exchange reachability information.
In an IP transit environment, BGP can be used to:
- advertise customer IP prefixes;
- receive routes from the transit provider;
- control which routes are accepted;
- influence outbound path selection;
- manage multiple upstream connections;
- withdraw routes when a path becomes unavailable.
BGP itself does not increase bandwidth or automatically reduce latency. Its role is to exchange routing information and apply policies that determine how traffic reaches different networks.
XLC’s BGP glossary guide explains how BGP manages routing between independent networks and why it matters for multi-carrier infrastructure.
What Affects IP Transit Performance?
The quality of IP transit depends on much more than the advertised port speed.
Carrier Selection
Different carriers have different backbone footprints, peering relationships, and routes into regional markets.
A provider with strong connectivity to Europe may not offer the same route quality into Asia or China.
Route Quality
Traffic can pass through multiple networks before reaching its destination. A shorter or better-connected route can provide lower latency and more consistent performance than a longer or congested path.
Peering
Direct peering with networks and Internet Exchanges can allow some traffic to reach its destination without relying on paid transit.
Geographic Location
The location of a network’s point of presence affects physical distance and the connectivity options available from that location.
XLC currently operates infrastructure across Los Angeles, Tokyo, and Hong Kong, providing network options across North America and APAC.
Congestion
Network congestion can increase latency and packet loss even when the underlying connection has high capacity. For this reason, real-world testing is more useful than evaluating transit solely by its advertised bandwidth.
What Are the Benefits of IP Transit?
Broad Internet Reach
IP transit provides connectivity to destinations beyond a network’s own infrastructure and direct interconnections.
Carrier Diversity
Multiple transit providers can reduce dependence on a single upstream and provide alternative routes.
Routing Flexibility
BGP allows network operators to manage routing policies and choose how traffic uses available connections.
Scalability
Transit capacity can be provisioned according to traffic requirements and increased as network demand grows, subject to the provider’s infrastructure and commercial terms.
Global Connectivity
Organizations serving users across multiple regions can combine IP transit with peering and private interconnections to build broader and more resilient network architectures.
Who Uses IP Transit?
IP transit is most relevant to organizations that operate their own network infrastructure.
Internet Service Providers
ISPs use transit to connect their customers and regional networks to destinations outside their own infrastructure.
Hosting and Data Center Providers
Hosting companies and data centers require upstream connectivity so customer servers and networks can communicate with the global Internet.
Cloud and SaaS Platforms
Cloud and SaaS providers can combine multiple transit connections with peering to support geographically distributed applications.
Gaming Platforms
Gaming platforms can use diverse transit and peering to improve connectivity between game servers and players across different regions.
Enterprises with Their Own Networks
Large companies operating multiple offices, data centers, or public-facing infrastructure can use IP transit as part of a multihomed network architecture.
Why Is IP Transit Important for Asia and China?
IP transit becomes particularly important when applications serve users across regions with different carrier and routing environments.
Traffic to mainland China can be affected by international routes, carrier relationships, and the network paths available between the source and destination.
A provider with direct relationships with major Chinese carriers can offer routing options beyond generic public Internet transit.
XLC’s network provides direct connectivity to China Telecom, China Unicom, and China Mobile, alongside Tier 1 transit and APAC Internet Exchange peering. The network currently offers Standard and Premium China routing options.
For Asia-facing workloads, the important question is therefore not only how much bandwidth is available, but also which carriers and routes carry the traffic.
IP Transit vs Private Cloud Connectivity
IP transit and private cloud connectivity solve different networking requirements.
IP transit provides broad Internet reachability. Private cloud connectivity provides a dedicated path between infrastructure and a cloud platform.
A company can therefore use IP transit for general Internet traffic while using a private connection for traffic between its dedicated servers and cloud environment.
XLC’s Direct Cloud Connect provides private connectivity from XLC infrastructure to AWS, Microsoft Azure, Google Cloud, Alibaba Cloud, and Oracle Cloud. The service is designed to bypass public Internet routing and provide more consistent connectivity between environments.
This creates a network architecture where different connection types serve different purposes:
- IP transit – general Internet connectivity;
- peering – direct exchange with connected networks;
- private cloud connectivity – dedicated paths between infrastructure and cloud platforms.
How Is IP Transit Usually Priced?
IP transit pricing depends on factors such as:
- committed bandwidth;
- port capacity;
- geographic location;
- carrier and network requirements;
- traffic profile;
- contract term;
- redundancy requirements.
Commercial models vary. Depending on the provider, transit may be priced around committed bandwidth or measured traffic, including models based on the 95th percentile.
The lowest price per Mbps is not necessarily the best choice. Route quality, redundancy, carrier diversity, and regional connectivity can have a greater operational impact than the headline bandwidth price.
How Should You Evaluate an IP Transit Provider?
When comparing providers, look beyond the advertised bandwidth.
Check the Upstream Carriers
Find out which transit providers carry the traffic and whether multiple independent upstreams are available.
Review Peering
Check which Internet Exchanges and major networks the provider peers with.
Evaluate BGP and Multihoming
Determine whether BGP is supported and whether multiple transit connections can be used for redundancy and traffic engineering.
Test Real Routes
Latency and route quality should be tested from the locations that matter to your users.
XLC provides a Network Looking Glass with ping, traceroute, and MTR testing from Los Angeles, Tokyo, and Hong Kong. This allows network routes and latency to be checked from XLC infrastructure before deployment.
Consider Regional Connectivity
If most traffic comes from Asia or China, evaluate the provider’s actual carrier relationships and routes into those markets rather than relying on a generic “global network” claim.
Review the SLA
Check the provider’s network availability commitment, redundancy model, and procedures for handling network failures.