service instance 20 ethernet
  description Internal site
  encapsulation dot1q 17
  rewrite ingress tag pop 1 symmetric
  xconnect 192.168.51.20 838969735 encapsulation mpls
   mtu 9202
 !
[download]

I don't think I know enough about those tools to help you, and you don't understand my questions.

Your code is also very hard to read for me.

A general solution is to parse your tree data into a nested array of hashes and to traverse that to output your new format.

But I don't know if that's really necessary because I don't understand the data.

I hope someone with deeper knowledge of your domain will pass by and can help you. :)

update

see also

Re: Cisco to Juniper - parser help

Cheers Rolf
_{(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery}