i bought a SIP account @ OVH.fr for
1.19€/month, unlimited calls in 40 countries :
Germany, Argentina, Australia, Austria, Belgium, Brazil, Canada, Chile, China, Cyprus, Colombia, Denmark, Spain, Metropolitan France, United Kingdom, Greece, Hong Kong, Hungary, Ireland, Israel, Italy, Kazakhstan, Luxembourg, Malaysia, Mexico, Norway, New Zealand, Panama, Netherlands, Poland, Portugal, Peru, Russia, Singapore, Slovakia, Switzerland, Sweden, Taiwan, Thailand, USA, Venezuela.
Maybe there is something similar in UK...
Well, I managed to set up my account in the DGA4130, and I can send / receive calls with a phone plugged into the FXS port
i had to tweak a little the file
/etc/config/mmpbxrvsipnet but not sure it was really necessary.
config mmpbxrvsipnet 'global'
option trace_level '2'
option radvision_trace_level '0'
config syslog 'syslog'
option registration '1'
option call_signalling '1'
option syslog_priority '6'
option hide_user_identity '0'
config network 'sip_net'
option user_friendly_name 'SIP network'
option cac '-1'
option transparent_soc_transmission '0'
option interface 'wan'
option local_port '5060'
option domain_name 'sip3.ovh.fr'
option primary_registrar_port '5060'
option secondary_proxy_port '0'
option transport_type 'UDP'
option reg_expire '3600'
option reg_expire_T_before '1'
option reg_back_off_timeout '60'
option reg_back_off_timeout_algorithm 'fixed'
option reg_back_off_timeout_max '900'
option reg_back_off_timeout_min '600'
option re_registration_mode 'ims'
option realm 'sip3.ovh.fr'
option realm_check '1'
option 401_407_waiting_time '0'
option dtmf_relay 'rfc2833'
option dtmf_relay_translation '0'
option timer_T1 '500'
option timer_T2 '4000'
option timer_T4 '5000'
option timer_B '32000'
option timer_D '50000'
option timer_F '32000'
option timer_J '32000'
option provisional_timer '1200'
option remote_hold_tone_enabled '0'
option sdp_direction_call_hold 'sendonly'
option sdp_direction_call_hold_answer 'recvonly'
option uri_clir_format 'standard'
option privacy_handling 'apply'
option rejection_response '486'
option no_answer_response '480'
option call_waiting_provisional_response '180'
option call_waiting_reject_response '486'
option reliable_provisional_response 'when_supported'
option forking_mode 'replace'
option ingress_media_timeout '1000'
option session_timer 'disabled'
option min_session_expires '90'
option session_expires '180'
option fail_behaviour 'stop'
option min_period_proxy_redundancy '0'
option escape_hash '1'
option escape_star '0'
option control_qos_field 'dscp'
option control_qos_value '40'
option realtime_qos_field 'dscp'
option realtime_qos_value '40'
option from_anonymous_handling 'withheld'
option sip_over_ipv6 '0'
option rtp_local_port_min '32000'
option rtp_local_port_max '39999'
option user_param_value 'phone'
option include_sip_instance '1'
option waiting_time_for_registration_on_400_or_503_response '60'
option hide_serial_number '0'
option use_domain_in_contact '1'
option use_domain_in_via '0'
option update_support '1'
option sdp_direction_attribute_media_level_only '1'
option registration_delay '5'
option enable_re_register_on_cancel_timeout '1'
option rport_in_via '1'
option optimized_authentication '1'
option repeat_ringing_interval '0'
option re_register_on_403 '0'
option check_ttl_for_dns_record '1'
option dns_query_timeout '5000'
option sip_message_max_size '4096'
option conference_release_call_after_transfer '0'
option disconnect_on_bye_response '1'
option cancel_invite_timer '64000'
option early_media_detection '0'
option user_agent 'Technicolor / VBNT-K / AGTEF_1.0.3 / AGTEF_1.0.3'
option primary_registrar 'sip3.ovh.fr'
option primary_proxy_port '5060'
option primary_proxy 'sip3.ovh.fr'
config profile 'sip_profile_0'
option network 'sip_net'
option password 'xxxxxxxx'
option uri '0033xxxxxxxxx'
option enabled '1'
option user_name '0033xxxxxxxxx'