LAN,
WAN and WEB based USPS CASS Certification/DPV Validation Server
Linux MailSERVE provides LAN, WAN and WEB based USPS CASS
certification and DPV delivery point validation service to
client applications using Perl, PHP, CGI, Java, ASP.NET, C/C++,
C#, VisualBasic, PowerBuilder or any programming interface
supporting TCP/IP sockets. Linux MailSERVE is USPS CASS certified
for ZIP, ZIP+4, DPBC, DPV and eLOT.
Choice
of Two Linux USPS CASS Certification/DPV Validation Access
Methods
Linux MailSERVE supports two client/server
access methods for USPS CASS certification and DPV delivery
point validation service. Both CASS certification/DPV validation
access methods are suitable for interactive address data acquisition
or batch address correction.
Simple
TCP/IP USPS CASS Certification/DPV Validation Method
The standard access method requires little
or no configuration and does not limit the number of clients
it can serve. The client initiates the request based on MailSERVE
host name and well-known port or service name, makes the request
and receives the USPS CASS certified response.
Linux
xinetd USPS CASS Certification/DPV Validation Method
The client application connects to the
USPS CASS certification and DPV validation service only once.
Linux xinetd forks a thin address validation proxy dedicated
to the client providing a private TCP/IP socket for address
service. The MailSERVE proxy uses ipc message queues and shared
memory CASS certifying addresses through Linux MailSERVE.
The xinetd method:
Provides
USPS CASS address validation and DPV validation access control
based on:
Address of remote host(s)
Time of access
Name of remote host(s)
Domain name of remote host(s)
Prevents denial-of-access attacks
by setting
Limits on the number of proxy servers for CASS certification
DPV validation
An upper bound on the number of processes
Limits on the number of connections a single host can initiate
Limits on the rate of incoming connections
xinetd will discontinue new services if the load exceeds
your specified limit
Logging:
Time when the CASS certification/DPV validation proxy server
was started
Remote host address
Who was the remote user (if the other end runs a RFC-931/RFC-1413
server)
How long the proxy server was running
Can be used as a proxy to other systems -- useful in combination
with ip_masquerading (or Network Address Translation - NAT)
in order to reach the internal network.
