Nomadix Access Gateway, User Manual

Page: 122 / 392

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110 System Administration
The figure above illustrates destination HTTP redirection, assuming a DNS query string for
www.example.com, a magic IP address of 1.1.1.1, and a portal page URL of
portal1.myhotel.com. Given this configuration, the following would apply:

A DNS query for www.example.com is intercepted by the NSE, which responds with
the magic IP address. Then, the subscriber’s browser sends an HTTP request to the
magic IP and sets the Host header to www.example.com.

The NSE will process the HTTP request and will analyze the Host header to find the
redirection URL that corresponds to www.example.com, which is
portal1.myhotel.com in this example. The NSE will then craft an HTTP redirection
response that contains the portal page URL, followed by a query string. The string
will include various redirection parameters, time-stamped and signed, if signing is
enabled for that entry (which it is not in this example).

The subscriber will follow the redirection string and will land on the portal page URL.
The portal will verify and analyze the query string and then will return the relevant
information (likely about the subscriber’s account status, depending on what the
portal is configured to handle).
User NSE External Server
portal1.myhotel.com /
DNS query: www.example.com?
* DNS response: 1.1.1.1
GET / HTTP/1.1…
Host:www.example.com
*** HTTP/1.1 200 OK
…
** HTTP/1.0 302 RD
Location:
portal1.myhotel.com/details?OS=..&UI=..&MA=..&RN=..&PORT=..&SIP=..&
TS=..&NO
NCE=..&SIGN=..&SIGNED=..&METHOD=..
…
* Magic IP Address
** Redirect Message
*** OK Accept Message
GET
details?OS=..&
UI=..&MA=..&RN=..&PORT=..&SIP=..&
TS=..&NONCE=..&SIGN=..&
SIGNED=..&METHOD=.. HTTP/1.1
Host:
portal1.myhotel.com