Server side redirection can be done by simply replying HTTP 302 to client.
If what you are asking is "How to go around server side redirection so that your Backbone callback can still be triggered?", then my solution will be following:
For example, when an user type a url http://yousite.com/blog/someid
on his browser, and you want to use Backbone callback to handle his request. Then you can let your server return:
<script> window.location="http://yoursite.com#blog/someid"</script>
Note we replace a /
into #
.
Or, you can let your server return (fragment allowed in Location):
HTTP/1.1 302 Found
Location: http://yoursite.com#blog/someid
Then your Backbone callback will be triggered.