Setting Linksys SPA2102 adapter for telephony

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Does anybody know how to set up Linksys SPA2102 phone adapter for telephony?
Internet cable from cable modem attached to Linksys adapter, another patch
from Linksys output connected to PC. Phone attached to phone jack in
Linksys. Phone not work, no signal in handset. Internet works OK. I tried to
enter into Linksys web interface via browser, but it does
not connects. Linksys may have another IP address (changed by provider). I
checked Default Gateway address on my desktop and yes, it have different IP,
I tried enter with this address but can no connects to web interface,
address not exist, page not loads.

Re: Setting Linksys SPA2102 adapter for telephony

On 8/16/2010 7:40 PM, astral wrote:
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The Cisco manuals and other information is found here.

Re: Setting Linksys SPA2102 adapter for telephony

astral wrote:
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I think you've probably got it wired up right. This is the stuff that
should be connected. Make sure the power adapter that plugs into the wall,
is connected.

   Cable_Modem ------ "Internet"            "Ethernet" ----------

                                Phone1  Phone2
                                   |        |
                                   |        |
                                Telephone  FAX
                                Base Unit  Machine

Now, an article here, suggests Linksys/Cisco have been excessively clever.
There is nothing wrong with what they've done, unless you're using two line
phones, and then you should be asking some questions. If you're using
a couple one line phones (which access only the center two wires of the RJ11),
you should be getting it to work.

I would try one telephone only at first. I have a feeling it might work,
if you plug it into Phone2. So your setup might work, like this.

   Cable_Modem ------ "Internet"            "Ethernet" ----------

                                Phone1  Phone2
                                   |        |
                                   x        |
                                         Base Unit

The Cisco box, takes the place of the phone company. These are the
kinds of things the Cisco box will be doing, on the Phone jack.

1) Convert +5V from wall adapter, to -48V for "bias". That is what
    makes the microphone and speaker work on the handset.

2) Deliver dial tone, when you go "off hook" with the handset.
    (You'll need a media player that can play an OGG audio file. I used
    audacity to listen to this.) Dial tone is cut off, once you start
    touch tone dialing.

3) When someone calls you, the Cisco box will have to generate the
    "ringing voltage", which is perhaps 90 volts AC at ~20Hz. That voltage
    was used, to resonate with the old mechanical ringers.

So the Cisco box has to work pretty hard, to make an analog phone line.
And needs that wall adapter connected, to do all that stuff.


Re: Setting Linksys SPA2102 adapter for telephony

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yes, the configuration you specified is what I have.  I have only one phone
attached to Phone1 port, no Fax. All worked normally,  but once the old
adapter has broken, I took the new adapter from the ISP (already
preconfigured by ISP), connected all cables, but phone not work. So I think
that some additional settings still should be configured. No signal in
handset, though there is normal "bips" sound when press on a telephone
keypad. Probably, phone number should be specified somewhere is phone
adapter settings in order to interface adapter with ISP gateway to public
switched telephone network (PSTN). How to access the adapter web

Re: Setting Linksys SPA2102 adapter for telephony

astral wrote:
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You would connect the computer directly to the "Ethernet" connector.
In your web browser, try

or just try it without the advanced word there. I found a user guide
here, which would be similar to what comes in the box.

I would make the connection this way.

1) Turn off the computer.
2) Run a cable from the computer to the "Ethernet" port on the SPA2102.
3) Turn on the SPA2102. That prepares it to run DHCP. Wait until it boots.
    That could take a few seconds.
4) Boot the computer. The computer should end up with an IP address
    of or higher. That will be on the same subnet as
    the of the adapter.
5) Try your web browser as above.
6) You'll need the username and password, to get into the SPA2102,
    if it was set by your ISP when the box was shipped to you. The
    user name is likely "user", with a custom password. If there is no
    login box at all, then a password has not been set.

The manual implies the unit needs an active source of Internet on the
"Internet" side of things, to make it work, but I refuse to believe
it would deny dial tone. There is supposed to be some kind of
interactive control possible via the telephone, and you could test
using that, to see if the box is responsive.

The manual says to use the touch tone pad on your phone while it is
plugged in, and press the star key four times " **** ". That is
supposed to initiate voice response from the SPA2102. If you make no
other touch tone keypad entries in the next minute (60 seconds), the voice
response will log out. That might be a test you can try, that the
SPA2102 is listening to the phone port.


Re: Setting Linksys SPA2102 adapter for telephony

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Thanks for detailed tips and manual. Unfortunately, I can not access web
menu. I tried above method, but no success.
I've checked also some settings of adapter by requesting them via handset
key pad, and voice response say that it is zero:
Internet IP address assigned to the adapter:
Network Mask(Subnet Mask):
Gateway IP Address:

Also, I tried option Enable/Disable WAN Access to the Web-based Utility -
but it ask for password.


Re: Setting Linksys SPA2102 adapter for telephony

On Wed, 18 Aug 2010 13:11:27 +0300, astral wrote:

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Is your modem more than just a modem but in fact a router/modem with
DHCP server?

Do you want your PAP to be allocated one by your router/modem?

If the answer to either of these questions is no, then you need
to use the hand set interface to allocate an IP address, subnet mask,
and gateway address appropriate to the network configuration of your
computer and modem.

It would help if you were to reveal what is the local IP address of
your modem and that of your computer because for obvious reasons the
IP address settings for your PAP must not conflict with these.

Re: Setting Linksys SPA2102 adapter for telephony

astral wrote:
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WAN Access would be access from the network side of the box. Such an access
method would be useful for tech support at your ISP, but not useful for

If the box really is password protected for all important settings,
perhaps it is time to talk to "tech support", with the people who
provided the device. If you purchased and own this device yourself,
then you'd be looking for the "reset" command, to reset the device to
defaults, which would wipe out any useful custom settings. I don't
recommend that, but I've used that on my own networking equipment
when I got in a bind. I've reset my modem/router several times,
and reprogrammed the settings on it, and that is because I own it
and no passwords were set by the ISP. At least some ISP-provided
devices now, allow the ISP to set a password, that the reset
procedure cannot remove (to prevent tampering).

The thing is, even if you program the address of the device, using the
interactive phone menu, you may still be faced with userid=user and
password=???????? when attempting to connect with the web browser.
By default, the web browser password is empty. (The web browser
password, isn't the same as the PPPOE userid and password fields in
the SPA2102. So don't be changing those just yet.)

On PDF page 38 of the User Guide, I find

LAN IP Address. Enter the local IP address of the Phone Adapter.
                 The default is

LAN Subnet Mask. Select the local subnet mask
                  The default is

OK, now the SPA2102 has its LAN address. Now your PC needs a LAN address.
There are a number of options. If you do nothing, and DHCP is turned off
on the SPA2102 when you connect directly to it, Windows will assign an
APIPA address 169.254.x.y . That probably isn't the best choice. You
can go into Windows networking, and change from "Obtain an IP address
automatically" to "Use the following IP address" and give yourself
something like . But that means writing down your
current PC network settings for TCP/IP, and putting them back

Or, you can try programming the SPA2102, for DHCP, so you don't have to
change Windows at all. On the same page of the User Guide:

DHCP Lease Time:                   Default 24 hours
DHCP Client Starting IP Address:   Default is
Number of Client IP Addresses:     Default is 50
Enable DHCP Server:                Once the other values are programmed,
                                    set this to "Yes" and submit the changes.

Maybe they haven't messed up the DHCP settings, in which case,
that will save you a lot of time reading the manual.

Once that is done, connect the Ethernet cable, power up the PC
and let it boot, and it should get an IP address via DHCP, with
no further bother to the settings on the PC. Your computer should
then be at, the SPA2102 at and you
should be able to use the web browser. You'll know immediately
whether you're going any further, when the password dialog box
comes up and asks for the password for user account "user".

Good luck,

Re: Setting Linksys SPA2102 adapter for telephony

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This device is provided by ISP in rent base, but service is poor enough.
I managed to find  IP address assigned to web interface of adapter (another
IPv4 address, not default, bit web interface was password
protected, so this does not help. Then I just set internet connection type
DHCP via phone key pad voice menu. After that  action I just got a dial tine
in a handset, but couldn't call, as after dialing a number there was an
answer "access restricted".  Internet worked normally. I just decided to do
factory reset of device via 73738, successful, after that I was able to
access web interface via default, sure I find all settings is
clean factory. I tried to set old values for IP address, subnet mask,
gateway IP address, but this not help and Internet is missing. And dont know
what mode adaper was set before resetting, Router/NAT mode or Bridge/Switch
mode. I tried both, but this not help, internet is missing. So now I just
directly connected ethernet cable from PC to cable modem, without adapter,
works fine, but telephony/router part is missing now.

Re: Setting Linksys SPA2102 adapter for telephony

astral wrote:
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When you got the "access restricted", you should have stopped there.
That would have been the time to contact the ISP, as the problem
could be at their end. Perhaps the service is keyed off the MAC
address of the SPA2102, and since you've changed the physical device,
something needs to be changed at their end ? Because you're using
a cable modem, I don't see anything in the picture, that authenticates
who you are and whether the VOIP portion should be working.

You're going to need to contact the ISP, to get all the proper settings.

It would be pretty hard to guess at them, and get it right.

Since you were able to reset the device, they must have the ability at
their tech support, to walk you through the necessary settings.


If the Internet type was ADSL, you might want Router/NAT mode, while
with a cable modem, I would guess either mode would work. The Router/NAT
mode would be useful for terminating PPPOE protocol, for example.
I expect a Cable Modem would not be using PPPOE. But your ISP will know
for sure.

The names of those modes, is probably a bit of a misnomer. I would not
expect the VOIP portion, to be covered by the routing function. The box
would likely look like this.

                 <------------------ SPA2102 ---------------->

   Cable_modem ------ VOIP --------- Router/NAT or bridged ------ LAN_connector
                      |  |
                  Phone1 Phone2

At least, that is how the picture was drawn at one time. The idea is,
the VOIP sits outside, due to the range of port numbers it needs to
see. (VOIP consists of call setup protocols, and data transport protocols.
And I thought one of those was rather wasteful of port numbers.)
It might not be practical to handle it via port forwarding. It would
also mean, the VOIP thing would not be covered by a firewall.
(Something I've always been curious about.)

In bridged mode, there would be no Network Address Translation. NAT
is a cheap form of firewall, and provides a limited level of protection
against a (port scanning) attack from the Internet. If you had a
router box connected to the right hand side of the diagram, to the LAN_Connector,
you may be able to leave the SPA2102 in bridged mode, as that router box would be
doing "Router/NAT" for you.

For example, this is how my Internet is set up. I did mine this
way, because I didn't like the router functions on the Speedtouch,
so I turned them off. My existing router box, provides the routing
functions. NAT is a way to support multiple computers on the same
Internet connection, and that is what it is doing for me in this
picture. In the SPA2102, the main value of the router/NAT function,
would be the NAT part. The router bit might be contributing things
like DHCP and gateway functions. My wired router box (on the right),
provides DHCP and serves up local addresses to my computers
( etc).

    --- phone_line ------ Speedtouch modem/router ------ Wired router box
          ADSL            <--- bridged mode ---->        <-- router/NAT -->

I'm really surprised the "reset" command was honored by the SPA2102.

On my current modem/router, the hardware has the capability to
ignore reset, based on the password being set. My modem/router
has several levels of password, so the modem/router critical
settings can be protected against user intervention. Since I
am the purchaser and owner of the modem, none of those passwords
were set, so I have total control (and total responsibility for
correct setup). It took me a couple days of fooling around with
it, until I was happy with the results. The documentation was
terrible, and the Speedtouch web interface just silly.
By comparison, the wired router box on the right, has a logical
and well thought out web interface, which makes it a pleasure
to work with. And that is most of the reason for my setup being
that way. I only interact with the wired router box now,
so no longer have to touch the Speedtouch box.

Good luck,

Re: Setting Linksys SPA2102 adapter for telephony

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would be
router/NAT -->
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There are nothing with ADSL - internet connection via broadband cable modem.
Internet connection via adapter has been restored, by setting in spa-2102
Connection Type: DHCP and the Mode: Bridge/Switch. But phone not working.
Its a regular PSTN phone connected via SPA2102 adapter, not VoIP phone
service. Problem most likely is at the ISP end. And yes, I think the phone
service is linked with the MAC address of the adapter, and since I've
changed the physical device,  they need to change something at their end.
But I want to make this myself. They given me adapter which wasn't
preprogrammed for full service. I should make a dump of configuration
settings of working adapter, that was my mistake. Where spa-2102 store its
configuration settings, and how to make dump? How to preprogram settings for
telephony, and how to change MAC address of adapter? I'll try to change it
to my old MAC address.

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