You can configure PPP VoIP on the Branch Gateway at Site A. Commands with footnotes are described at the end of the configuration procedure.

• Loopback and PMI interfaces configuration:

  Gxxx-001# interface loopback 1
  Gxxx-001(if:Loopback 1)# ip address 149.49.54.82 24
  Done!
  Gxxx-001(if:Loopback 1)# pmi
  The Primary management interface has changed. Please copy the running configuration to the start-up configuration file, and reset the device.
  Gxxx-001(if:Loopback 1)# exit
  Gxxx-001# copy running-config startup-config
  Gxxx-001# reset

• VLAN interface configuration:

  Gxxx-001# interface Vlan 1
  Gxxx-001(if:Vlan 1)# ip address 149.49.54.24
  Done!
  Gxxx-001(if:Vlan 1)# exit
  Gxxx-001# interface Vlan 2
  Gxxx-001(if:Vlan 2)# ip address 11.11.11.1 24
  Done!
  Gxxx-001(if:Vlan 2)# exit

• Serial interface configuration:

  Gxxx-001# interface serial 4/1
  Gxxx-001(if:Serial 4/1)# ip address 2.2.2.1 24
  Gxxx-001(if:Serial 4/1)# mtu 300

  Note:

  Some LAN data applications do not support fragmented packets. In this case, do not change the MTU from its default of 1500.

  Gxxx-001(if:Serial 4/1)# bandwidth 128

• VoIP configuration:

  Gxxx-001(if:Serial 4/1)# ip rtp header-compression
  Gxxx-001(if:Serial 4/1)# ip rtp compression-connections 20 (4)
  Gxxx-001(if:Serial 4/1)# ip rtp port-range 2048 3028       (5)
  Gxxx-001(if:Serial 4/1)# exit

• Static routes configuration:

  Gxxx-001# ip default-gateway 4/1

* Description of footnoted commands (also applies to identical stages in configuring Site B):

(1) At this stage you apply Priority 7 to Voice Control traffic.

(2) At this stage you apply Priority 6 to RTP traffic.

(3) At this stage you apply maximum trust between 802.1p priority and DSCP.

(4) At this stage the number of connections (20) depends on the number of phones.

(5) At this stage you are matching the RTP port range to that of the Gateway.

(6) At this stage the default queue size is 6, and since RTP is enabled you can double the VoIP queue size.