Return to Technical Information Index

Configuring callVantage


Update January 14, 2014


I originally posted this is circa 2004 and this information is very outdated – However, I recently received a phone call from a concerned citizen inquiring how I had access to their 'IP' address, which was – the caller stated that I “even had their” -


I believe the D-Link VoIP was a router with a receptacle to connect a standard telephone and make phone calls over the internet using ATT CallVantage phone service - I believe that ATT CallVantage VoIP service was discontinued in 2009 -


Please understand that are PRIVATE network IP addresses, not public - Private networks all over the world are using those same IP addresses - the is not an address, it is a subnet mask -


A public IP address is assigned by an Internet Service provider to every device that connects to the internet - however, note that most home computers do NOT have a public IP address - they are , for example, connected to a DSL/cable modem or a WiFi hotspot - those devices contain a router which creates a private network - typically, the router might have a private network IP address of and when a computer connects to it, the router assigns a private IP address of to that computer - the DSL/Cable Modem or WiFi hotspot has a public IP address assigned by the ISP -


Here is an article from Wise Geek:


The subnet mask is used to define the local private network - means that all devices on that network must have the same first three octets - for example the private network IP addresses of all devices on a private network with a subnet mask of must begin with, leaving the last octet available for as a unique identifier for each device on the network -


Here's an article on subnet masks:


I hope this addendum clarifies the issue that the IP addresses in this example are PRIVATE network IP addresses used in my home network and in fact are NOT anyone’s public internet IP address– LLH



Equpment -

D-Link DVG-1120M: VoIP Gateway

Linksys BEFSX41: EtherFast Cable/DSL Firewall Router with 4-Port Switch/VPN Endpoint

Linksys EPSX3: EtherFast 10/100 PrintServer


Disclamer: I know nothing about networks - I'm an old 8-bit assembly language programmer that loves to torture myself with Microsoft products (and apparently networks too) -


The following arrangement and settings will work and work well - This particular arrangement of settings uses Fixed IPs so that port forwarding can be utuilized in the D-Link Gateway for those programs that need to receive unsolicited TCP/IP packets from the 'net (chat programs, web cam server, etc) - I puzzled through most of it myself - a friend of mine did explain a few issues to me - Many thanks Doug!




Run an ethernet straight-through cable from the DSL/Cable modem to the D-Link Gateway - plug the service phone into the D-Link Gateway -


You of course need to configure the D-Link Gateway with your broadband connection information, following the directions that came with the callVantage service or the D-Link Gateway -


At this point you should be able to reboot and have VoIP phone service available, irrespective of the status of the rest of the components (off/on/not hooked up/hooked-up, not working/hooked-up, working) -


The Linksys Gateway (BEFSX41) is overkill by a mile, but I had one that wasn't being used for anything else - in this arrangement it is only being used as a switch - the WAN (and WAN port) is not used, consequently it's firewall isn't being used either - a simple switch would work just fine -


Techinically an ethernet CROSSOVER cable ought to be run from the D-Link LAN to one of the four Linksys Gateway LAN ports - However, per the user guide [Chapter 3, figure 3-1, page 9], ports 1-3 and the DMZ port auto-detect crossover and straight-through cables, so either is acceptable if you have a BEFSX41 Gateway, or a Gateway/Router/Switch with auto-detect -


NOTA BENE: the WAN port on the Linksys is UNUSED -


The rest of the connections should be as generally described in the normal installation - that is an ethernet straight-through cable from each PC network card to a Linksys Gateway unused LAN port, another from a Linksys Gateway LAN port to the Linksys PrintServer -


If you don't have a PrintServer, simply ignore any comments/instructions - if you have a different device, you 'should' be able to connect those devices in the same fashion as the PrintServer - unfortunately, I can't help you with other devices -




There is only ONE network with several devices (hosts) connected together - in case you didn't know (and I didn't, the first 3 octets define a network, in this case I used - This is the default used by the D-Link Gateway - each host on the network MUST be unique - the D-Link Gateway (default) used 1, I used 10 for one computer, 20 for another computer, 99 for my Linksys PrintServer and 88 for Linksys Gateway - the default host for the Linksys Gateway is 1, but that needs to be changed to avoid conflict with the D-Link Gateway - remembering to change it for all devices, the network assignment is somewhat arbitrary - The Linksys Gateway and PrintServer uses as a default -


A tip: You can only access the Linksys Gateway and PrintServer configuration panels when the network IP of your computer match the network IP of the device - let's say that your computer, the Linksys Gateway and PrintServer all have an IP addy - you change the Linksys Gateway to - at that point, you will no longer be able to access the Linksys Gateway configuration panel - change the Linksys PrintServer to and you will no longer be able to access the Linksys PrintServer configuration panel - change your computer IP assy to and you will then be able to gain access to the Linksys configuration panels - remember AVOID duplicate host Octets -


Another tip: You should set any devices providing DHCP services to start with address 100 - if you assign hosts in the 1-99 range, then your host assignments and any DHCP assignments should peacefully coexist - to be honest, the only reason I had to (more like chose to) mess with fixed IPs is because a few chat programs want to be able to send unsolicited TCP/IP packets to your computer and the usual way to do that is to assign fixed IP addys and use port forwarding - also, I do run a local web cam on occasion -




D-Link DVG-1120M Gateway:

WAN settings should come via DHCP from your ISP when the Gateway logs onto your ISP account -

LAN Settings

LAN IP Adresss 

LAN Netmask

Dynamic IP Assigment

Start IP Address

IP Range 100

[Highest IP address assigned by DHCP is - 100+100-1]



PC Network card settings - Command Prompt>Ipconfig /all

Windows 2000 IP Configuration

        Host Name . . . . . . . . . . . . : YourHostName

        Primary DNS Suffix  . . . . . . . :

        Node Type . . . . . . . . . . . . : Broadcast

        IP Routing Enabled. . . . . . . . : No

        WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Local Area Connection:

        Connection-specific DNS Suffix  . :

        Description . . . . . . . . . . . : Network Everywhere Fast Ethernet Adapter(NC100 v2) #2

        Physical Address. . . . . . . . . : 00-03-6D-1B-4C-9B

        DHCP Enabled. . . . . . . . . . . : No

        IP Address. . . . . . . . . . . . :

        Subnet Mask . . . . . . . . . . . :

        Default Gateway . . . . . . . . . :

        DNS Servers . . . . . . . . . . . :



I set IP address to

The Default Gateway comes from the D-Link Gateway

The DNS Servers are those used by my ISP and can be found on the D-Link Gateway configuration panel



The Linksys Gateway (BEFSX41) - Fixed IP Address:

Device IP Address

Subnet Mask

The following are unused, but these are 'safe' settings

WAN connection type to "Obtain IP automatically" 

DHCP Server, Starting Address: Network.100



PrintServer - Fixed IP Address:

Device IP Address

Subnet Mask

Gateway IP Address



Problems - not understood -


The DNS servers on the PC ethernet card should be able to be set to the D-Link Gateway IP Address ( instead of the ISP DNS servers - but it won't work - and it should -



The D-Link has an alternative interesting method to set a fixed IP for a device -

DHP Confirguration

Static IP Assigment [Edit]

Put in the MAC address of the the device (say your PC's network card)

IP Address

Net Mask

Default Gateway

DNS1 Server [your ISP's DNs]

Satus Enable


Click save and it will set your network card for those values -



If you have more questions, send me an email and I will be happy to explain more - this information is equipment specific - and to be honest, I have no other equipment to check it with - I would assume that any modern Linksys Gateway/Router/Switch would function pretty much as the BEFSX41 - and should function as well -