DDR uses a Point-to-Point Protocol (PPP) link, which handles all networking functions such as sending, receiving and compressing the signals between two computers on the internet.
In other words, the PPP link uses telephone lines to send signals between you and the computer containing your desired website when you wish to make a connection to the internet.
DDR connections are inherently slow and service fees are charged like phone calls depending on the uptime.
These include but are not limited to the type of physical cable used in the connection, the distance the data is being sent, and the protocols used to send the information.
These two factors become exceedingly important when a company has multiple locations that need to communicate with one another on a regular basis.
Leasing cable lines can be needlessly expensive if information isn’t constantly being sent back and forth between branches.
Access Control Lists (ACLs) can be used to restrict which type of traffic is allowed to establish a connection.
Additionally, it is equally crucial to filter out any native Ethernet traffic which would otherwise cause an unwanted connection to initialize.
When configuring dynamic routing protocols to communicate over a DDR connection, their update packets must be classified as interesting traffic.
Depending on the dynamic routing protocol being used, setting their updates as interesting traffic might cause the connection to be initialized often.
It is common to see static routes defined for these connections in order to avoid extra service charges.
[4] Dialer maps are configured on each interface to specify which numbers to dial and how long to stay on the line waiting for the receiving end to pick up.