Making a VoIP call with the Cisco 837 ADSL router

Question

I would greatly appreciate if could please provide some technical assistance to my questions below:
Is it possible to make a VoIP call between two 837 ADSL Cisco routers over a 1Mbps ADSL broadband connection?
If so, can I configure this VoIP connection using either a PPPoE or ATM WAN link?
Is it possible to make a VoIP call using a Cisco 837 Router while simultaneously surfing the Internet? In other words do I need two public IP addresses i.e. one for accessing the internet and one for making the VoIP call or is one static IP address obtained from my ISP sufficent.
It is possible to configure QoS parameters (e.g. RSVP, Voice precedence, Voice codec selection) on this 837 router using PPoE or can it only be done using an ATM WAN interface?
Does the Cisco 837 router support both the H.323 and SIP communication protocols? Do I need to purchase a certain IOS operating system version for VoIP calling?
Does the VoIP dial peers need to be configured with both a POTS and VoIP phone numbers or is only one number required?
Do I need to obtain a special VoIP number from my VoIP service provider? or can I use existing POTS numbers or made up numbers within the dial peers as this situation involves making a private VoIP call between two branch offices using 837 ADSL routers and not via a VoIP service provider.
Finally, can I use POTS ordinary telephones with the Cisco 837 for making VoIP calls or do I strictly need to purchase VoIP phones?
My apologies for the number of questions asked here but I currently need to know the technical ability of the Cisco ADSL 837 as I am thinking of employing these routers in my company organisation.
I await your feedback in due course.
Thanks,
Martin Healy

Answer 1

Hi,
I give you a sample config of my router.
class-map voice
match access-group 101
policy-map mypolicy
class voice
priority 128
class class-default
fair-queue 16
ip subnet-zero
gateway
interface Ethernet0
ip address 20.20.20.20 255.255.255.0
no ip directed-broadcast (default)
ip route-cache policy
ip policy route-map data
interface ATM0
ip address 10.10.10.20 255.255.255.0
no ip directed-broadcast (default)
no atm ilmi-keepalive (default)
pvc 1/40
service-policy output mypolicy
protocol ip 10.10.10.36 broadcast
vbr-nrt 640 600 4
! 640 is the maximum upstream rate of ADSL
encapsulation aal5snap
bundle-enable
h323-gateway voip interface
h323-gateway voip id gk-twister ipaddr 172.17.1.1 1719
h323-gateway voip h323-id gw-820
h323-gateway voip tech-prefix 1#
router eigrp 100
network 10.0.0.0
network 20.0.0.0
ip classless (default)
no ip http server
access-list 101 permit ip any any precedence critical
route-map data permit 10
set ip precedence routine
line con 0
exec-timeout 0 0
transport input none
stopbits 1
line vty 0 4
login
voice-port 1
local-alerting
timeouts call-disconnect 0
voice-port 2
local-alerting
timeouts call-disconnect 0
voice-port 3
local-alerting
timeouts call-disconnect 0
voice-port 4
local-alerting
timeouts call-disconnect 0
dial-peer voice 10 voip
destination-pattern ........
ip precedence 5
session target ras
dial-peer voice 1 pots
destination-pattern 5258111
port 1
dial-peer voice 2 pots
destination-pattern 5258222
port 2
dial-peer voice 3 pots
destination-pattern 5258333
port 3
dial-peer voice 4 pots
destination-pattern 5258444
port 4
end