The DnsE16 service allows anyone running on the 21 network to use host names instead of IP addresses to keep track of servers.
Right now, you would need to run commands like:
$ 21 buy http://10.248.12.34:2001/service/endpoint
Using the new service, you could set it up so the following can be done with a host name instead:
$ 21 buy http://my-endpoint.21/service/endpoint
In the above example, you can see that it is using the my-endpoint.21 host name instead of an IP address.
See the Github project to find out more information and learn how to use it.