Дано: Cеть с динамической маршрутизацией OSPF.
Задача: Необходимо организовать телефонную связь между двумя офисами, используя маршрутизаторы ESR-12V.

В качестве адреса источника и назначения для пакетов телефонии использовать адреса на loopback- интерфейсах.

В версии ПО 1.34.2 добавлена возможность назначать адрес источника для пакетов, исходящих со встроенного PBX-сервера (source-address <адрес>).
Конфигурация маршрутизаторов для решения задачи будет выглядеть так:

hostname R1

router ospf 1
  redistribute connected
  area 1.1.1.1
    enable
  exit
  enable
exit

sip profile 1
  enable
  sip-domain address 192.0.2.1
  proxy primary
    enable
    ip address proxy-server 192.0.2.1
    registration
    ip address registration-server 192.0.2.1
  exit
  proxy primary mode parking
  no echo-canceller
  transfer dtmf inband
exit

interface gigabitethernet 1/0/8
  ip firewall disable
  ip address 203.0.113.1/30
  ip ospf instance 1
  ip ospf area 1.1.1.1
  ip ospf
exit
interface loopback 1
  ip address 192.0.2.1/32
exit
interface voice-port 1
  sip user phone 111
exit

pbx
  source-address 192.0.2.1
  ruleset fxs_ports
    rule 10
      pattern '222,1,Dial(SIP/${EXTEN}@192.0.2.2)'
      enable
    exit
  exit
  ruleset from_sip_trunk
    rule 10
      pattern '111,1,Dial(SIP/${EXTEN},,t)'
      enable
    exit
  exit
  profile fxs_ports
    client friend
    codec allow g711a
    codec allow g711u
    codec allow g729
    ruleset fxs_ports
  exit
  profile trunk_to_SIP_server
    type external
    client friend
    codec allow g711a
    codec allow g711u
    security level invite-port
    qualify 10000
    host-address 192.0.2.2
    ruleset from_sip_trunk
  exit
  user 111
    profile fxs_ports
  exit
  enable
exit


hostname R2

router ospf 1
  redistribute connected
  area 1.1.1.1
    enable
  exit
  enable
exit

sip profile 1
  enable
  sip-domain address 192.0.2.2
  proxy primary
    enable
    ip address proxy-server 192.0.2.2
    registration
    ip address registration-server 192.0.2.2
  exit
  proxy primary mode parking
  no echo-canceller
  transfer dtmf inband
exit

interface gigabitethernet 1/0/8
  ip firewall disable
  ip address 203.0.113.5/30
  ip ospf instance 1
  ip ospf area 1.1.1.1
  ip ospf
exit
interface loopback 1
  ip address 192.0.2.2/32
exit
interface voice-port 1
  sip user phone 222
exit

pbx
  source-address 192.0.2.2
  ruleset fxs_ports
    rule 10
      pattern '111,1,Dial(SIP/${EXTEN}@192.0.2.1)'
      enable
    exit
  exit
  ruleset from_sip_trunk
    rule 10
      pattern '222,1,Dial(SIP/${EXTEN},,t)'
      enable
    exit
  exit
  profile fxs_ports
    client friend
    codec allow g711a
    codec allow g711u
    codec allow g729
    ruleset fxs_ports
  exit
  profile trunk_to_SIP_server
    type external
    client friend
    codec allow g711a
    codec allow g711u
    security level invite-port
    qualify 10000
    host-address 192.0.2.1
    ruleset from_sip_trunk
  exit
  user 222
    profile fxs_ports
  exit
  enable
exit