In some disconnected environments with low or instable network bandwidth, it might be necessary in such situation to deploy two or more identical SharePoint farms and perform content replication/synchronization between them.

It’s important to mention that SharePoint 2010 product supports natively only one way content replication through Content Deployment It is important to be aware that content deployment is a one-way process: content is deployed from a source site collection to a destination site collection. The content deployment feature does not support round-trip synchronization from source to destination and back
again. Creating new content or changing existing content on the destination site collection can cause content deployment jobs to fail.

if you are interested in Content Deployment I highly recommend to refer to this technet article

In order to perform two ways replication, a third party application should be used, the drawback of this is that Microsoft doesn’t provide support or guarantee on 3^rd party applications. However I have listed below some considerations that should be taken into consideration when evaluating a 3^rd party replication software for SharePoint 2010:

• Item level replicaiton: the ability to replicate web application , site collection , or site.
• Replicating SharePoint content across limited bandwidth connections and use a minimized network bandwidth when performing the replication (data compression).
• The ability to replicate the changed item only or full replication.
• Replicate permissions.
• Scheduling:  to provide manual or timer job scheduling.
• conflict resolutioncapabilities between source and destination.
• Reporting capability: generate different type of reports to describe the replication status.
• Integrated administration and operations page within SharePoint administration page no need to use a separate administration console.

I personally recommend to have a look at one of the two below vendors (again this is my own personal recommendation and does not reflect Microsoft point of view in anyway):

• Syntergy  Replicator

• Company website (http://www.syntergy.com) 

• Product overview  (http://www.syntergy.com/products/sharepoint/replicator/replicatorSP-ds.pdf)

• Product Versions (http://www.syntergy.com/products/sharepoint/replicator/SyntergyProductComparison.pdf)

• Demo – Video  (http://www.youtube.com/watch?feature=player_embedded&v=s1GRWLV5pwQ)

• AvePoint

• Company website (www.avepoint.com)

• Product overview (http://www.avepoint.com/sharepoint-replication-docave/)

• Demo Video (http://www.avepoint.com/assets/movie/eLearning_Center/DocAve-SharePoint-Administrator/DocAve-SharePoint-Administrator.html)

• Download Trial (http://www.avepoint.com/resources/free-trial-downloads/)