URI segment is not working while "query strings" is working

[eluser]Unknown[/eluser]
If both method can't be supported how can i access a page having some required and option params?

Typically I would put the requided param in the "path" segment and the optional params in the query string part. Something like www.xyz.com/controller/action/req_param1/req_param2?opt_param_name1=opt_param_value1&opt_param_name2=opt_param_value2

Since they are optional params, it's not really possible to have a fix order if we put them in the path. For example in www.xyz.com/controller/action/req_param1/req_param2/opt_param the last segment could be either opt_param_value1 or opt_param_value2.

What would be the way to solve optional params. I do want to use the path style URI.

Thanks much