Openwrt and sipproxy why I am unable to perform a call via a softphone?

I have setup in my router openwrt and I try to perform a call using my provider's VOIP settings that I retrieved for its router that provided. My network settings are the following:

config interface 'loopback'
	option device 'lo'
	option proto 'static'
	option ipaddr '127.0.0.1'
	option netmask '255.0.0.0'

config globals 'globals'
	option ula_prefix 'fdd2:a40d:d919::/48'


config device 'wan_dsl0_dev'
	option name 'dsl0'
	option macaddr XX:XX:XX:XX:XX:XX

config atm-bridge 'atm'
	option vpi '1'
	option vci '32'
	option encaps 'llc'
	option payload 'bridged'
	option nameprefix 'dsl'

config dsl 'dsl'
        option annex 'b'
	option ds_snr_offset '0'
        option line_mode 'vdsl'
        option tone 'auto'        
        option firmware '/lib/firmware/vr9-B-dsl.bin' 

config device
	option name 'br-lan'
	option type 'bridge'
	list ports 'lan1'
	list ports 'lan2'
	list ports 'lan3'
	list ports 'lan4'

config interface 'lan'
	option device 'br-lan'
	option proto 'static'
	option ipaddr '192.168.1.1'
	option netmask '255.255.255.0'
	option ip6assign '60'

config interface 'wan'
    option device 'dsl0.835'
	option proto 'pppoe'
	option username 'username'
	option password 'password'
    option ipv6 'none'
    option keepalive '10'
    option mtu '1492'
	list dns '1.1.1.1'
    option peerdns '0'

config interface voip
	option device 'dsl0.837'
	option proto 'dhcp'

config interface 'wan6'
	option device '@wan'
	option proto 'dhcpv6'

As you can see, voip uses the vlan dsl0.837. Also, I have configured the siproxy like that as well:

config siproxd general
	# Custom options allow using OpenWRT network names, and defaults should
	# work out-of-the-box. If your SIP devices do not REGISTER externally,
	# you may also need to open firewall ports: tcp/udp 5060, udp 7070-7089.

	option interface_inbound lan
#	option interface_outbound dsl0.837

# All other documented siproxd configuration directives are supported. Use
# a UCI 'option' for single-instance directives, and UCI 'list' entries for
# directives that allow multiple instances, per the examples below.

	# Define low-level network devices, overriding interface_in/outbound:
#	option if_inbound eth0
	option if_outbound dsl0.837


	# Enable DEBUG logging for configuration messages:
#	option debug_level 0x00000100
#	option silence_log 0

	# Load two plugins: one that logs SIP call details to syslog, and one
	# that strips out G.729, GSM codecs:
#	list load_plugin 'plugin_logcall.so'
#	list load_plugin 'plugin_codecfilter.so'
#	list plugin_codecfilter_blacklist G729
#	list plugin_codecfilter_blacklist GSM

daemonize 1
masked_host=ngn.hol.net
outbound_proxy_host = ngn.hol.net
outbound_proxy_port = 5060

Then In my computer connected via ethernet to the LAN has ekiga configured like that: But despite successfully connecting to voip, I am unable to perform a call to my cellphone (my provider offers landline call via SIP/VOIP). My provider is Vodafone in Greece. I attempted ta call sip:^my_cellphone_number^@192.168.1.1 (router's ip) but I am unable to do so. So do you know why? My firewall settings are the following as well:

config defaults
	option syn_flood	1
	option input		ACCEPT
	option output		ACCEPT
	option forward		REJECT
# Uncomment this line to disable ipv6 rules
#	option disable_ipv6	1

config zone
	option name		lan
	list   network		'lan'
	option input		ACCEPT
	option output		ACCEPT
	option forward		ACCEPT

config zone
	option name		wan
	list   network		'wan'
	list   network		'wan6'
	option input		REJECT
	option output		ACCEPT
	option forward		REJECT
	option masq		1
	option mtu_fix		1

config forwarding
	option src		lan
	option dest		wan

# We need to accept udp packets on port 68,
# see https://dev.openwrt.org/ticket/4108 
config rule
	option name		Allow-DHCP-Renew
	option src		wan
	option proto		udp
	option dest_port	68
	option target		ACCEPT
	option family		ipv4

# Allow IPv4 ping
config rule
	option name		Allow-Ping
	option src		wan
	option proto		icmp
	option icmp_type	echo-request
	option family		ipv4
	option target		ACCEPT

config rule
	option name		Allow-IGMP
	option src		wan
	option proto		igmp
	option family		ipv4
	option target		ACCEPT

config rule
	option name		Allow-VOIP
	option src		lan
	option proto		udp	
	option src_port		5060
	option family           ipv4            
        option target           ACCEPT

config rule                            
        option name             Allow-VOIP  
        option src              lan       
        option proto            udp               
        option src_port         7070-7080            
        option family           ipv4      
        option target           ACCEPT     

# Allow DHCPv6 replies
# see https://dev.openwrt.org/ticket/10381 
config rule
	option name		Allow-DHCPv6
	option src		wan
	option proto		udp
	option src_ip		fc00::/6
	option dest_ip		fc00::/6
	option dest_port	546
	option family		ipv6
	option target		ACCEPT

config rule
	option name		Allow-MLD
	option src		wan
	option proto		icmp
	option src_ip		fe80::/10
	list icmp_type		'130/0'
	list icmp_type		'131/0'
	list icmp_type		'132/0'
	list icmp_type		'143/0'
	option family		ipv6
	option target		ACCEPT

# Allow essential incoming IPv6 ICMP traffic
config rule
	option name		Allow-ICMPv6-Input
	option src		wan
	option proto	icmp
	list icmp_type		echo-request
	list icmp_type		echo-reply
	list icmp_type		destination-unreachable
	list icmp_type		packet-too-big
	list icmp_type		time-exceeded
	list icmp_type		bad-header
	list icmp_type		unknown-header-type
	list icmp_type		router-solicitation
	list icmp_type		neighbour-solicitation
	list icmp_type		router-advertisement
	list icmp_type		neighbour-advertisement
	option limit		1000/sec
	option family		ipv6
	option target		ACCEPT

# Allow essential forwarded IPv6 ICMP traffic
config rule
	option name		Allow-ICMPv6-Forward
	option src		wan
	option dest		*
	option proto		icmp
	list icmp_type		echo-request
	list icmp_type		echo-reply
	list icmp_type		destination-unreachable
	list icmp_type		packet-too-big
	list icmp_type		time-exceeded
	list icmp_type		bad-header
	list icmp_type		unknown-header-type
	option limit		1000/sec
	option family		ipv6
	option target		ACCEPT

config rule
	option name		Allow-IPSec-ESP
	option src		wan
	option dest		lan
	option proto		esp
	option target		ACCEPT

config rule
	option name		Allow-ISAKMP
	option src		wan
	option dest		lan
	option dest_port	500
	option proto		udp
	option target		ACCEPT

# allow interoperability with traceroute classic
# note that traceroute uses a fixed port range, and depends on getting
# back ICMP Unreachables.  if we're operating in DROP mode, it won't
# work so we explicitly REJECT packets on these ports.
config rule
	option name		Support-UDP-Traceroute
	option src		wan
	option dest_port	33434:33689
	option proto		udp
	option family		ipv4
	option target		REJECT
	option enabled		false

Do I also need to open extra ports as well?