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IP Transit or Dedicated Internet Access (DIA): Which is Right for Me?

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You need to procure the correct public Internet connection for your business. There are several options including broadband Internet, dedicated Internet access, IP Transit, direct settlement-free or paid peering arrangements, and others. 

But, enterprises and mid-to-large-sized organizations usually weigh the differences between just two: Dedicated Internet Access (DIA) and IP Transit. This blog takes a closer look at which service might be right for you.

Starting with the Bottom Line

Within Zayo, we often say that DIA is the right service if the Internet is FOR your business (it’s an essential tool that allows your local or national business to run), and IP Transit is the right service if the Internet IS your business (it’s what you sell, you use it to connect to other networks, or it’s the primary gateway for global clients to access your applications and services).

What is Dedicated Internet Access (DIA)?

DIA – sometimes also called Fiber Internet or Ethernet Dedicated Internet – is a premium service that offers a direct and exclusive connection to the Internet. Unlike traditional broadband that shares bandwidth among multiple users, DIA ensures that your business gets a dedicated, consistent and reliable connection. Different companies provide DIA differently, so when shopping, ensure that you always have access to the entire bandwidth purchased.

Example: A mid-sized law firm would purchase DIA services for dedicated Internet access to cloud-based legal research databases, client management systems, and secure email communication. DIA provides consistent upload and download speeds, which is crucial for large file transfers, video conferencing with clients, and accessing remote servers.

What is IP Transit?

IP Transit also provides direct connections from a customer’s network to the global Internet. A fundamental element of IP Transit is that the Internet connection occurs in a data center rather than an office location, and is used to connect to specific networks, or autonomous system numbers (ASNs). Each IP Transit provider (like Zayo) establishes peering arrangements with other Transit providers, Tier 1 Internet providers, select Tier 2 providers, and hyperscalers. By connecting to a Tier 1 provider (like Zayo) with IP Transit, you gain access to their global peering exchange points and thereby access to the global Internet. 

Example: A media provider needs IP Transit to make content easily and readily accessible by end-users. By connecting with a Tier 1 ISP over BGP, they obtain global access and ample capacity through the ISPs other connected networks (like CDNs) to help deliver streamed movies to their end-users. 

Both IP Transit and DIA are designed to provide robust Internet connectivity for businesses. Each offers high-speed, reliable Internet connections that can support a range of business applications. Fundamentally, the difference comes down to the composition of the service.

Internet Service Providers (ISPs) that offer both differentiate between the services because they cater to different needs and operate in distinct ways. Understanding these differences can help you choose the right service based on your specific business requirements.

Typical Characteristics of DIA and IP Transit
DIAIP Transit
1. Access locationAny enterprise locationData center connection
2. How many ISPsSingle-homed (one ISP)Multi-homed (multiple ISPs)
3. RoutingSimplified routing (default routing)Complex routing (BGP), custom communities
4. BandwidthSmaller (100 Mbps – 10 Gbps)Bigger (10 Gbps – 100 Gbps+)
5. CostLower Equipment CostsHigher $/MbHigher Equipment CostsLower $/Mb
Bottom LineInternet is FOR your businessInternet IS your business.

Access Location

Access location is code for how you use, buy, and consume Internet bandwidth. If you’re a small-to-midsize enterprise whose core business relies on the Internet to reach your customers and applications, you’ll need the reliability of a dedicated Internet connection (read: broadband alone may not be enough). For you, the main considerations of Internet access are:

  • Price – a good value for the performance
  • Availability – the service reliably provides the bandwidth you paid for, even at peak traffic times
  • Quick access – the service can be delivered to your access location when you need it

If you’re a carrier or large enterprise whose business is content, your considerations are more extensive. Your connection(s) to the Internet occur from a data center where large amounts of data are processed. In addition to the three cited above, your considerations include:

  • Peering capacity – how your ISPs balance their network traffic among all peers
  • Network architecture – how your ISPs distribute peering points, and manage capacity 
  • Network reach – how much of the global Internet is covered by your ISPs’ own networks
  • Price – not just overall cost per month, but price per bit transmitted ($/Mb)

Single vs. Multi-Homed Internet

Single-homed and multi-homed dedicated Internet access refer to different configurations of connecting to the Internet, primarily in terms of redundancy and reliability. Here’s a breakdown of the differences:

Single-Homed Internet Access

A single-homed setup uses one ISP for Internet connectivity. Your ISP will then provide access to the whole of the Internet. 

Things to consider:

  • With a single connection, if that ISP experiences downtime or issues, your Internet connection will be affected
  • Generally less expensive than multi-homed setups – you’re using only one ISP
  • Easier to manage and configure since there is only one connection and routing path
  • Best suited for smaller businesses without big IP teams

Multi-Homed Internet Access

A multi-homed setup uses two or more ISPs for internet connectivity. You use IP Transit to connect to specific networks and access their peering relationships. With carrier diversity at the forefront of most network engineers’ minds, IP Transit customers establish Internet connectivity in a multi-homed fashion.

Things to consider:

  • If one ISP fails, the others can maintain the Internet connection, ensuring higher availability
  • Generally more expensive – you’re using multiple ISPs and potentially more sophisticated hardware and configuration
  • More complex to manage and configure due to multiple connections and routing paths, and requires in-house knowledge of networking protocols like BGP (Border Gateway Protocol), and how to manage route announcements
  • Ideal for larger businesses, other carriers, hyperscalers, and mission-critical applications where uptime and reliability are crucial

Summarized:

Typical Characteristics: Single- vs. Multi-Homed Internet Access
FeatureSingle-HomedMulti-Homed
Number of ISPsOneTwo or more
RedundancyNoneHigh
CostLower monthly, higher $/MbHigher monthly, lower $/Mb
ConfigurationSimplerMore complex
Best for:Smaller businesses and non-critical applicationsLarger businesses and critical applications

Routing

With a DIA connection, your ISP manages all routing on your behalf. Since most IP Transit customers connect in a multi-homed fashion to the Internet, they’ll need their own ASN, and internal expertise in managing prefix announcements over Border Gateway Protocol (BGP) for Internet connectivity. Here’s an overview of the key areas of BGP expertise needed with IP Transit:

  1. You’ll need to understand the fundamentals of BGP
  • How BGP operates, including its use as a path-vector protocol that exchanges routing information between autonomous systems (ASes)
  • BGP’s attributes (e.g., AS Path, Next Hop, Local Preference, MED) and their role in determining the best path for routing data
  • How routes are advertised, accepted, and processed between BGP peers
  1. You’ll need configuration skills
  • How to configure BGP on routers for the initial set-up, including establishing peer relationships with other BGP-speaking routers
  • Creating and managing route maps, prefix lists, and access lists to control which routes are advertised or accepted
  • Implementing inbound and outbound route filtering to ensure proper traffic flow and avoid route leaks
  1. You’ll need to monitor and maintain your network
  • Understanding BGP sessions, tracking route changes, and detecting anomalies
  • Analyzing BGP logs and utilize diagnostic commands to troubleshoot
  • Knowing how to optimize BGP configurations to ensure efficient routing and minimize latency
  1. You’ll need to consider failover and redundancy 
  • Designing BGP configurations for redundancy among multiple ISPs to ensure seamless failover
  • Establishing link aggregation (LAG) to enable traffic load balancing across multiple connections
  • Implementing route aggregation to reduce the size of the routing table and improve performance
  1. You’ll need security expertise as well
  • Implementing prefix lists and access control lists (ACLs) will secure BGP sessions
  • Configuring BGP session authentication will protect against unauthorized access
  • Look for ISPs with good route filtering that prevents the acceptance or advertisement of malicious or incorrect routes

It’s a lot of internal BGP expertise for sure. However, in-house expertise offers enhanced control, customization, and security while potentially being more cost-efficient in the long run. Internal teams provide higher reliability, align closely with business goals, and can offer immediate support. Customers of IP Transit have weighed these benefits against the initial investment and ongoing operational costs compared to purchasing DIA services, and have often landed on IP Transit.

Bandwidth

Your bandwidth needs alone could point to DIA or IP Transit as your Internet access solution. If you’re unsure of the bandwidth you’ll need, we’ve provided a table below that provides a rough idea, given the number of people in your organization who will be using the Internet service, and the number of devices you expect to connect:

Planning Your Internet Bandwidth
Internet speed# of people# of devices
500 Mbps – 1 Gbps10-2020-40
1 Gbps – 5 Gbps20-10040-200
5 Gbps – 10 Gbps100-200200-400
10 Gbps – 50 Gbps200-1,000400-2,000
50 Gbps – 100 Gbps>1,000>2,000

As you can see, we typically recommend 50 Mbps per user, and 25 Mbps per device. While this will vary depending on your applications, it’s a safe estimate. Another view into planning your bandwidth is looking at how bandwidth-hungry your applications are:

Planning Your Internet Bandwidth
Application TypeTypical Mbps
Browsing and email1-5 Mbps per user
Streaming videoHD 5-10 Mbps per streamUHD 25 Mbps per stream
Video callsSD 1-4 Mbps per participantHD 2-8 Mbps per participant
Music streaming<1-2 Mbps per stream
Webinars for training and education5-25 Mbps per viewer
CRM systems (e.g. Salesforce)1-10 Mbps per user
ERP systems (e.g. Oracle)1-10 Mbps per user
Productivity suites (e.g. MS Office)1-10 Mbps per user

While all of these are approximations and can vary based on factors such as the number of users simultaneously accessing applications or the type of information being uploaded and downloaded, these are general usage patterns required for each.

Cost

IP Transit will likely provide overall lower costs in the long run, but requires investments in BGP and IP in-house expertise upfront. DIA provides simplicity, predictability, and lower upfront costs. Depending on your organization’s rate of Internet bandwidth use and growth, DIA may wind up costing more in the long term.

We’ve included some common cost considerations below:

Cost Considerations
Cost ElementDIAIP Transit
Bandwidth FeesFlat monthly fee based on bandwidth tierLower $/Mb, priced on a per-Mbps basis
Port FeesUsually included in the serviceMay incur additional charges
Hardware CostsUsually included in the serviceHigher upfront investment
IT Staff SalariesMinimal – ISP expertise runs the serviceSkilled engineering required
Network MaintenanceNone – the ISP maintains their networkNone – the ISPs maintain their networks
Monitoring ToolsThe ISP provides a user portalPortal provided by the ISPs, 3rd parties, or developed in-house

Conclusion

IP Transit and DIA use the same underlying technology. The services address the differences in how organizations consume the Internet. 

Large enterprises, hyperscalers, carriers, and massive online content providers rely on the enhanced control, customization, and tight business controls an internal team of IP engineers offers. The sheer amount of bandwidth these organizations consume in order to provide their services to the broader world dictates how they consume the Internet they purchase. IP Transit offers the flexibility and in-house control they require while saving money in the long term.

Smaller enterprises simply need Internet that performs well with a predictable monthly fee from a trusted ISP. These organizations turn to DIA.

Explore Zayo’s full suite of network connectivity solutions, including IP Transit and DIA: https://www.zayo.com/services/network-connectivity/

Explore our Network Connectivity Solutions

Explore Zayo’s full suite of network connectivity solutions, including IP Transit and DIA.

Explore our Network Connectivity Solutions

Explore Zayo’s full suite of network connectivity solutions, including IP Transit and DIA.