More about Packing

As per the blog that discusses Shipping Director built-in variables:

Rate Request Type - When Packaging, can be set by user to indicate the way that rate requests are made to other rate calculation methods when Packaging

Note that the Rate Request Types pertain when rate requests are made to other rate calculation methods (i.e. external methods like FedEx, UPS, etc.)

An external method like FedEx does its own "packing" - it will take the items in the cart, and "approximate" the number of packages based on dimensions/weight.   I've posted nopCommerce forum topics about how poor the algorithm is, and that's why I provide here at nopTools.com a modified version of the FedEx plugin(which was adopted by nopCommerce in version 2.50), and also created SD’s First Fit Single Box packing.

“OneRequestForAllPackages” is the default setting - it calls the external shipping plugin just once, and that plugin will do its own approximation of the number of packages.  That's when it's useful to use the new FedEx plugin which supports "PackByOneItemPerPackage" - then, the packing done by SD is respected by the FedEx plugin (no additional "approximate packing" is done).

With “OneRequestPerPackage”, SD will make multiple requests (one per package) to the external plugin, and aggregate the like named carrier options.   Liked named aggregation means that when FedEx returns a "Ground" rate for each separate request, they are added together, and the customer sees a single "Ground" option/rate.

“OneRequestPerSender” is used when using the Packing record type’s Sender Expression.  Here too, SD will make multiple requests (one per sender) to the external plugin, and again does liked named aggregation.  This blog about Packing by Warehouseprovides a good explanation.