View the Exhibit.
Based on the network topology above, which of the following command sets could you issue on Router1 so that
calls are routed to Phone2?
A.
dial-peer voice 1 voip
destination-pattern 555….
port 1/0/0
B.
dial-peer voice 1 pots
destination-pattern …….
port 1/0/0
C.
dial-peer voice 1 voip
destination-pattern 555….
port 1/0/1
D.
dial-peer voice 1 pots
destination-pattern 5550717
port 1/0/1
Explanation:
You could issue the following command set on Router1 so that calls are routed to Phone2:
dial-peer voice 1 pots
destination-pattern …….
port 1/0/0
The dial-peer voice tag [pots | voip] command is used to define how calls are routed to destination endpoints on
either the public switched telephone network (PSTN) or a Voice over IP (VoIP) network. To define call routing
for the PSTN, you should issue the dial-peer voice command with the pots keyword. The tag value is any
number in the range from 1 through 2147483647 that you assign to the dial peer as an identifier. To define call
routing for a VoIP network, you should issue the dial-peer voice command with the voip keyword. In this
scenario, Phone2 is connected to the PSTN. Therefore, dial peer 1 should be configured as a pots dial peer.
The destination-pattern command is used to match both inbound and outbound dial peers. The sequence of
dialed digits that will be matched for a dial peer can contain the digits 0 through 9, the asterisk (*), and the
pound sign (#). In addition, you can use a period (.) as a wildcard symbol to refine the dialing pattern or to
match multiple dial strings for a single dial peer. In the command set above, dial peer 1 is configured to match
destinations that contain seven digits. Each digit in the pattern is represented by a single .wildcard. Phone2 is
addressed with a seven-digit telephone numberĶ¾ therefore, the dial peer’s destination-pattern command should
be configured to match a sevendigit pattern.
The port command is used by a voice router to match inbound plain old telephone service (POTS) dial peers
and to determine where to route outgoing POTS dial peers. In this scenario, the Cisco Unified Communications
Manager Express (CME) router port connected to the PSTN is foreign exchange office (FXO) port 1/0/0.
Therefore, the dial peer should be configured to send traffic from Router1 destined for Phone2 through port
1/0/0.
Issuing the following command set on Router1 will not route calls to Phone2:
dial-peer voice 1 voip
destination-pattern 555….
port 1/0/0
Although the destination-pattern command will match the Phone2 telephone number and the port command is
configured for the port on Router1 that is connected to the PSTN, the dial-peer voice command has been
issued with the voip keyword. Phone2 is connected to the PSTN, not to the VoIP network. In addition, the
session target command, not the port command, must be issued to route a voip dial peer. The session target
command configures a dial peer with a network address for routing voice traffic over an IP network. The
network address can be an IP address or a host name, depending on whether a Domain Name System (DNS)
server is configured and available to resolve host names.
Issuing the following command set on Router1 will not route calls to Phone2:
dial-peer voice 1 voip
destination-pattern 555….
port 1/0/1
Although the destination-pattern command will match the Phone2 telephone number, the port command is
configured for the foreign exchange station (FXS) 1/0/1 port on Router1, not the outbound port that is
connected to the PSTN. In addition, the dial-peer voice command has been issued with the voip keyword.
Therefore, the previous command set is an invalid configuration.
Issuing the following command set on Router1 will not route calls to Phone2:dial-peer voice 1 pots
destination-pattern 5550717
port 1/0/1
Although the dial-peer voice command is correctly configured and the destination-pattern command will
explicitly match the telephone number for Phone2, an incorrect port has been specified for the outbound traffic.
The command set above would work if the port 1/0/0 command were issued instead of the port 1/0/1 command.
You cannot connect an FXS port to the PSTN.Cisco: Understanding Inbound and Outbound Dial Peer Matching on IOS Platforms: Non DID Case