While intranets have become a must for most organizations because they allow for centralized, efficient information sharing and management, suppliers, partners and customers often need to get their hands on (and probably contribute to) some of that very same information as well … which, of course, is not possible with an intranet that is accessible only to the organization’s internal employees. 

The logical solution to this problem is to create an extranet SharePoint site directly from your actual farm. If you’re currently managing an on-premises SharePoint, be sure to consider all the crucial questions before moving forward.

Internal and External Factors 

Odds are you’re already pretty familiar with SharePoint’s features and gaps for allowing external users to connect. When evaluating an extranet project, you might rapidly consider which SharePoint third-party solution needs to be installed to offer a log-in/sign-in page and password reset capabilities to end-users.

In this case, form-based authentication might be more suited for these users than claim-based authentication. You might have a solid plan on how you are going to manage security and permission levels to control which external users will have access to the view and edit functionalities.

These are all good questions related to SharePoint that need to be answered before creating an extranet site. But what about considerations outside of SharePoint, such as networking security, traffic, performance and additional hardware and software requirements/implications for your global infrastructure?

If you’re thinking of deploying an on-premises SharePoint extranet for your business, prepare to spend a considerable amount of time and money. These factors are often neglected and are only taken into account once it’s too late -- when everybody else is ready to deploy. In many cases, infrastructure experts need to be involved much earlier in the process.

That being said, organizations are becoming more and more inclined to consider alternative solutions such as the cloud for their extranet site hosting, with the objective of completing projects more quickly and remaining within budget.

Public Cloud Deployment

The fastest deployable option to consider would be signing up for SharePoint hosting services on a multi-tenant platform, also known as public cloud or SaaS. The low cost of this model makes it an appealing option, but many hit a wall of significant limitations after a few days of testing.

If you are looking for the most basic collaborative features, hosted SharePoint Foundation solutions usually offer unlimited user access -- which can definitely be a plus when it comes to adding as many external users as required. But if you need more advanced SharePoint Server features, then licensing might be a better choice.

In a shared or public hosting platform, you wouldn't be able to leverage your own corporate license agreements with Microsoft, meaning you’ll end up paying Microsoft double for using their software. At worst, it can work, but it’s not really cost-effective.

Or perhaps you’re thinking of connecting your on-premises intranet with your extranet that’s located in any type of public cloud hosting platform (either at your time of deployment or in a subsequent phase)? Forget about it. Even if you do find a provider that will let you do it, I would have serious concerns about data security and the provider’s professionalism.

Hybrid or Private Cloud Deployment

All this may lead you to choose a private cloud hosting solution for your extranet. In my opinion, it really is the best of both worlds: the control and flexibility of an on-premises deployment, but for the cost and scalability of a public cloud solution such as Office 365.

The private cloud is an option that’s often overlooked -- which is difficult to fathom considering that it’s probably the best option for most mid-sized organizations looking to combine an extranet with their intranet. The SharePoint private cloud hosting model allows you to have a hybrid deployment (intranet stays in-house and extranet is hosted elsewhere) or to have your two sites on one farm.

What does running a hybrid solution entail? Mainly that your company’s intranet stays in-house, while your extranet is hosted in the cloud. The tricky part can be making it a smooth experience for internal users who have to move from the extranet to the intranet and vice versa (without authentication prompts). The good news is SharePoint 2013 has a new claims feature: You get to choose the characters for the claim type, making the connection between farms much easier than with SharePoint 2010.

While you may probably start with completely distinct environments (intra and extranet), you can gradually make connections and publish some content from your on-premises intranet to your extranet hosted elsewhere and vice versa.

After a while though, chances are you will simply find it easier to move your complete intranet to this same private cloud. Cross-site publishing will enable your two sites to easily connect, plus it’s easy to implement with minimum involvement required from your SharePoint administrators. It’s no coincidence that Steve Ballmer claims private cloud will be one of the biggest hosting trends in the mid- and large-sized segment in the coming years.

Editor's Note: Read more on SharePoint deployment options in SharePoint 2013: The Role of Hybrid Deployments