ko.mapping.fromJS(newData, mapping, modelToUpdate)


var mapping = {}; //define your mapping (see documentation or blog post)

function ViewModel(){
    var self = this;

    self.model = ko.mapping.fromJS({}, mapping);
    self.hub = $.connection.myHub();
    self.hub.client.updateModel = function(data){
       ko.mapping.fromJS(data, mapping, self.model);
    };
    self.hub.start().done(function(){
       //you could either make a call or have the "OnConnected" method trigger an 'updateModel'
    });
}