My ISP provided me with a Sercomm modem for use with my Windows 7 PC but
with very minimal information about its characteristics and capabilities.
Stamped into the back of the case is:
ES2251
DOSCSIS 3.1 eMTA
Input 12V, 2.0A
A label on the back has a serial number, two MAC addresses, and "PC
2.0". It also has:
Made in Philipines HW VER: 1.3
SD 10
An E-mail with images showing the above to Sercomm's U.S. sales office remains unanswered. Does anyone have documentation on this modem?
My ISP provided me with a Sercomm modem for use with my Windows 7
PC but with very minimal information about its characteristics and capabilities.
Stamped into the back of the case is:
ES2251
My ISP provided me with a Sercomm modem for use with my Windows 7 PC but
with very minimal information about its characteristics and capabilities.
Stamped into the back of the case is:
ES2251
DOSCSIS 3.1 eMTA
Input 12V, 2.0A
A label on the back has a serial number, two MAC addresses, and "PC
2.0". It also has:
Made in Philipines HW VER: 1.3
SD 10
An E-mail with images showing the above to Sercomm's U.S. sales office remains unanswered. Does anyone have documentation on this modem?
My ISP provided me with a Sercomm modem for use with my Windows 7 PC but
with very minimal information about its characteristics and capabilities.
Stamped into the back of the case is:
ES2251
DOSCSIS 3.1 eMTA
Input 12V, 2.0A
A label on the back has a serial number, two MAC addresses, and "PC
2.0". It also has:
Made in Philipines HW VER: 1.3
SD 10
An E-mail with images showing the above to Sercomm's U.S. sales office remains unanswered. Does anyone have documentation on this modem?
David E. Ross wrote:
My ISP provided me with a Sercomm modem for use with my Windows 7 PC but
with very minimal information about its characteristics and capabilities.
Stamped into the back of the case is:
ES2251
DOSCSIS 3.1 eMTA
Input 12V, 2.0A
A label on the back has a serial number, two MAC addresses, and "PC
2.0". It also has:
Made in Philipines HW VER: 1.3
SD 10
An E-mail with images showing the above to Sercomm's U.S. sales office
remains unanswered. Does anyone have documentation on this modem?
Google "ES2251 DOSCSIS 3.1 eMTA" and download the user manual from cloudfront.net.
Ed
My ISP provided me with a Sercomm modem for use with my Windows 7 PC
but with very minimal information about its characteristics and
capabilities.
Stamped into the back of the case is:
ES2251
DOSCSIS 3.1 eMTA
Input 12V, 2.0A
A label on the back has a serial number, two MAC addresses, and "PC
2.0". It also has:
Made in Philipines HW VER: 1.3
SD 10
An E-mail with images showing the above to Sercomm's U.S. sales office remains unanswered. Does anyone have documentation on this modem?
David E. Ross wrote:
My ISP provided me with a Sercomm modem for use with my Windows 7 PC
but with very minimal information about its characteristics and
capabilities.
Stamped into the back of the case is:
ES2251
DOSCSIS 3.1 eMTA
Input 12V, 2.0A
A label on the back has a serial number, two MAC addresses, and "PC
2.0". It also has:
Made in Philipines HW VER: 1.3
SD 10
An E-mail with images showing the above to Sercomm's U.S. sales office
remains unanswered. Does anyone have documentation on this modem?
My ISP provider gave me one of these (not your model) and I had them put it in bridge mode so I could use my own router and not screw with them.
My connection to the Internet is through Spectrum. Because I was having problems with Spectrum's E-mail service (but not with my primary
Sunset.net service), Spectrum sent a technician to my house at no cost
to me. The technician connected Spectrum's Sercomm modem to my Netgear router without any questions.
From the User Guide suggested by Ed Cryer, it appears that I might not
need a router. Instead, I can try connecting my and my wife's PCs
directly to the modem. However, I am concerned whether I will then be
able to change what DNS addresses I use; I review and update my choice
of DNS about quarterly. With a separate modem, I change the DNS address
both on my and my wife's PCs and on my router.
On Sun, 13 Sep 2026 14:10:38 -0700, David E. Ross wrote:
[snip]
My connection to the Internet is through Spectrum. Because I was having
problems with Spectrum's E-mail service (but not with my primary
Sunset.net service), Spectrum sent a technician to my house at no cost
to me. The technician connected Spectrum's Sercomm modem to my Netgear
router without any questions.
From the User Guide suggested by Ed Cryer, it appears that I might not
need a router. Instead, I can try connecting my and my wife's PCs
directly to the modem. However, I am concerned whether I will then be
able to change what DNS addresses I use; I review and update my choice
of DNS about quarterly. With a separate modem, I change the DNS address
both on my and my wife's PCs and on my router.
A modem (not router) probably allows only one device to be connected.
On Sun, 13 Sep 2026 14:10:38 -0700, David E. Ross wrote:
[snip]
My connection to the Internet is through Spectrum. Because I was having
problems with Spectrum's E-mail service (but not with my primary
Sunset.net service), Spectrum sent a technician to my house at no cost
to me. The technician connected Spectrum's Sercomm modem to my Netgear
router without any questions.
From the User Guide suggested by Ed Cryer, it appears that I might not
need a router. Instead, I can try connecting my and my wife's PCs
directly to the modem. However, I am concerned whether I will then be
able to change what DNS addresses I use; I review and update my choice
of DNS about quarterly. With a separate modem, I change the DNS address
both on my and my wife's PCs and on my router.
A modem (not router) probably allows only one device to be connected.
On Mon, 9/14/2026 9:43 AM, Mark Lloyd wrote:
On Sun, 13 Sep 2026 14:10:38 -0700, David E. Ross wrote:
[snip]
My connection to the Internet is through Spectrum. Because I was having >>> problems with Spectrum's E-mail service (but not with my primary
Sunset.net service), Spectrum sent a technician to my house at no cost
to me. The technician connected Spectrum's Sercomm modem to my Netgear
router without any questions.
From the User Guide suggested by Ed Cryer, it appears that I might not
need a router. Instead, I can try connecting my and my wife's PCs
directly to the modem. However, I am concerned whether I will then be
able to change what DNS addresses I use; I review and update my choice
of DNS about quarterly. With a separate modem, I change the DNS address >>> both on my and my wife's PCs and on my router.
A modem (not router) probably allows only one device to be connected.
The user manual shows a router being connected downstream of the modem.
Normally, the VOIP-ATA would also imply a router (my separate ATA works that way).
Maybe you could just hook a four port switch to the modem. If the modem
has no web interface, that kind of decides how your computer room is going
to work, for you.
The VOIP-ATA needs authentication, so the modem would need a web interface and
"a few settings". I don't think you can do VOIP-ATA without some routing.
It needs multiple connections, has a control plane and a data plane,
in typical bloated telecom style :-) What's really neat about VOIP-ATA,
is how it can work when your DNS drops out. I find that more than a bit humorous.
Page 3 shows a typical use diagram, the backup lead-acid battery is missing from the diagram, and would also be a typical use thing (for VOIP-ATA backup). The backup battery powers the modem, the separate router would drop, but the two RJ11 connectors on the VOIP-ATA on the modem would continue to work.
The hardware would not be kind to the backup battery, so you
would not expect more than maybe four hours from it. The hardware
has to do QAM (Quadrature Amplitude Modulation) as well as run RF receivers for the cable signal, and that takes some current to do that continuously
for four hours, just so you can have a dial tone. My network stack
is a similar porker here, modern broadband is pretty demanding.
Maybe a fiber optic connection could potentially be a bit better
on backup power drain.
https://d15yx0mnc9teae.cloudfront.net/sites/default/files/2021-04/Spectrum%20eMTA%20User%20Guide.pdf
Paul
The diagram in the User Guide shows a Wifi router connected to the modem through an ethernet port. We do not use Wifi.
The User Guide does not describe how the two unused ports (near the top
of the back of the modem) are used. The diagram shows a phone connected through one of those ports. That would be for a VOIP phone, but we do
not have VOIP phones.
Over all, the User Guide is very weak.
On 9/14/2026 6:43 AM, Mark Lloyd wrote:
On Sun, 13 Sep 2026 14:10:38 -0700, David E. Ross wrote:
[snip]
My connection to the Internet is through Spectrum. Because I was having >>> problems with Spectrum's E-mail service (but not with my primary
Sunset.net service), Spectrum sent a technician to my house at no cost
to me. The technician connected Spectrum's Sercomm modem to my Netgear
router without any questions.
From the User Guide suggested by Ed Cryer, it appears that I might not
need a router. Instead, I can try connecting my and my wife's PCs
directly to the modem. However, I am concerned whether I will then be
able to change what DNS addresses I use; I review and update my choice
of DNS about quarterly. With a separate modem, I change the DNS address >>> both on my and my wife's PCs and on my router.
A modem (not router) probably allows only one device to be connected.
Combination modem-routers are quite common now. There are two currently unused ports on the back of the modem. I did not look at them carefully
to see if they are ethernet ports, which are needed to connect our PCs.
The diagram in the User Guide shows a Wifi router connected to the
modem through an ethernet port. We do not use Wifi.
The User Guide does not describe how the two unused ports (near the
top of the back of the modem) are used. The diagram shows a phone
connected through one of those ports. That would be for a VOIP
phone, but we do not have VOIP phones.
You have 1 LAN port on the modem. You need a router to have
2, or more, LAN ports.
"David E. Ross" <nobody@nowhere.invalid> wrote:[]
[]The User Guide does not describe how the two unused ports (near the
top of the back of the modem) are used. The diagram shows a phone
connected through one of those ports. That would be for a VOIP
phone, but we do not have VOIP phones.
There is only *ONE* Ethernet port. If not using wifi then you are using
The phone ports are connected using twisted pair to landline phones, not[]
for VOIP (SIP) phones. As the manual states, page 2, "Voice 1-2: Use to connect *ANALOG* telephones to the device". Those phone ports go to
either directly to landline phones, or to the twisted pair wiring in
to your telcom (which would be your ISP). Again, those phone port are[]
*not* for VOIP/SIP phones. They are for landline phones. If your
On 2026/9/15 18:52:57, VanguardLH wrote:
"David E. Ross" <nobody@nowhere.invalid> wrote:[]
[]The User Guide does not describe how the two unused ports (near the
top of the back of the modem) are used. The diagram shows a phone
connected through one of those ports. That would be for a VOIP
phone, but we do not have VOIP phones.
There is only *ONE* Ethernet port. If not using wifi then you are using
The phone ports are connected using twisted pair to landline phones, not[]
for VOIP (SIP) phones. As the manual states, page 2, "Voice 1-2: Use to
connect *ANALOG* telephones to the device". Those phone ports go to
either directly to landline phones, or to the twisted pair wiring in
to your telcom (which would be your ISP). Again, those phone port are[]
*not* for VOIP/SIP phones. They are for landline phones. If your
In other words, the box includes the ATA (analogue telephone adapter)
needed to use an analogue 'phone with VoIP, inside it. Possibly two of
them, unless the sockets are just wired in parallel. Or, if your part of
the world is continuing to have landlines available and the box is
connected to the original copper 'phone line, then it just passes
through those sockets (possibly with some filtering). I didn't think
many parts of the world were keeping landlines much beyond the next few months.
In UK, which is going through the VoIP transition, those ISPs who
support VoIP are supplying a box (usually referred to as a "router"
here, but actually contains MoDem, router, switch, and Wifi
transceivers) with _one_ analogue 'phone socket (i. e. the ATA built
into the box), or have already done so in anticipation of the change; I
am not aware of any of them supplying one with _two_ 'phone sockets. Not
all ISPs - more accurately now, ICPs - _are_ supporting VoIP. A large proportion of UK homes have switched to mobile (cellular) for 'phone
purposes anyway, so will not notice the loss of the landline, though businesses may want to keep their number (so have to go VoIP). [UK
numbers are distinguishable: mobile numbers start with 07, landline
numbers do not.]--
J. P. Gilliver. UMRA: 1960/<1985 MB++G()ALIS-Ch++(p)Ar++T+H+Sh0!:`)DNAf
From the User Guide suggested by Ed Cryer, it appears that I might not >>>> need a router. Instead, I can try connecting my and my wife's PCs
directly to the modem. However, I am concerned whether I will then be >>>> able to change what DNS addresses I use; I review and update my choice >>>> of DNS about quarterly. With a separate modem, I change the DNS address >>>> both on my and my wife's PCs and on my router.
On 9/15/2026 9:28 AM, David E. Ross wrote:
[snipped}
From the User Guide suggested by Ed Cryer, it appears that I might not >>>>> need a router. Instead, I can try connecting my and my wife's PCs
directly to the modem. However, I am concerned whether I will then be >>>>> able to change what DNS addresses I use; I review and update my choice >>>>> of DNS about quarterly. With a separate modem, I change the DNS address >>>>> both on my and my wife's PCs and on my router.
[snipped]
Okay. I was curious about bypassing my Netgear router. It is 5+ years
old and only passes 100 MB/sec while Spectrum and its modem can deliver faster.
I will keep the Netgear router. Even if it is not the fastest, it works quite well and is fast enough.
David E. Ross <nobody@nowhere.invalid> wrote:
Strange configuration - I would expect four or at minimum two Ethernet ports - but apparenly this provider assumes everyone is using Wi-Fi.
A modem (not router) probably allows only one device to be connected.Combination modem-routers are quite common now.
There are two currently
unused ports on the back of the modem. I did not look at them carefully
to see if they are ethernet ports, which are needed to connect our PCs.
Okay. I was curious about bypassing my Netgear router. It is 5+ years
old and only passes 100 MB/sec while Spectrum and its modem can deliver faster.
I will keep the Netgear router. Even if it is not the fastest, it works quite well and is fast enough.
In other words, the box includes the ATA (analogue telephone adapter)
needed to use an analogue 'phone with VoIP, inside it. Possibly two of
them, unless the sockets are just wired in parallel. Or, if your part of
the world is continuing to have landlines available and the box is
connected to the original copper 'phone line, then it just passes
through those sockets (possibly with some filtering). I didn't think
many parts of the world were keeping landlines much beyond the next few months.
Religion is a name for opinion that cannot be argued about.--
[Heard on Radio 4, 2010-10-18, 9:xx.]
On Tue, 15 Sep 2026 19:40:17 +0100, J. P. Gilliver wrote:
[snip]
In other words, the box includes the ATA (analogue telephone adapter)
needed to use an analogue 'phone with VoIP, inside it. Possibly two of
them, unless the sockets are just wired in parallel. Or, if your part of
the world is continuing to have landlines available and the box is
connected to the original copper 'phone line, then it just passes
through those sockets (possibly with some filtering). I didn't think
many parts of the world were keeping landlines much beyond the next few
months.
I've talked to some people (US, east Texas) who still have an old copper phone line. They say the company will be discontinuing service in
November. They will be using fixed wireless.
[snip]
I think you want a sig seperator here. Thats -- (dash-dash-space) on its own line.
Religion is a name for opinion that cannot be argued about.
[Heard on Radio 4, 2010-10-18, 9:xx.]
On Tue, 15 Sep 2026 19:40:17 +0100, J. P. Gilliver wrote:
[snip]
In other words, the box includes the ATA (analogue telephone adapter)
needed to use an analogue 'phone with VoIP, inside it. Possibly two of
them, unless the sockets are just wired in parallel. Or, if your part of
the world is continuing to have landlines available and the box is
connected to the original copper 'phone line, then it just passes
through those sockets (possibly with some filtering). I didn't think
many parts of the world were keeping landlines much beyond the next few
months.
I've talked to some people (US, east Texas) who still have an old copper phone line. They say the company will be discontinuing service in
November. They will be using fixed wireless.
On 17/09/2026 2:58 am, Mark Lloyd wrote:
On Tue, 15 Sep 2026 19:40:17 +0100, J. P. Gilliver wrote:
[snip]
In other words, the box includes the ATA (analogue telephone adapter)
needed to use an analogue 'phone with VoIP, inside it. Possibly two of
them, unless the sockets are just wired in parallel. Or, if your part of >>> the world is continuing to have landlines available and the box is
connected to the original copper 'phone line, then it just passes
through those sockets (possibly with some filtering). I didn't think
many parts of the world were keeping landlines much beyond the next few
months.
I've talked to some people (US, east Texas) who still have an old copper
phone line. They say the company will be discontinuing service in
November. They will be using fixed wireless.
I live about 70km/40miles north of Melbourne, Victoria, Australia and I still have a Landline Phone (which also handles my Internet connection via a modem box near the phone socket).
As I understand it, the phone connection is Digital to the big box in the street then analogue (copper line) to my home wall socket (which is actually in the Master Bedroom).
I also have a mobile phone. ;-P
On 15 Sep 2026 17:38:50 GMT, Frank Slootweg wrote:
David E. Ross <nobody@nowhere.invalid> wrote:
[snip]
Strange configuration - I would expect four or at minimum two Ethernet ports - but apparenly this provider assumes everyone is using Wi-Fi.
Multiple ethernet ports and WiFi are things you'd expect on a router, not
a modem, although I have heard of a modem with 2 ethernet ports that could be combined for higher speed.
I live about 70km/40miles north of Melbourne, Victoria, Australia and I still have a Landline Phone (which also handles my Internet connection
via a modem box near the phone socket).
As I understand it, the phone connection is Digital to the big box in
the street then analogue (copper line) to my home wall socket (which is actually in the Master Bedroom).
I also have a mobile phone. ;-P
On 2026/9/17 11:25:10, Daniel70 wrote: []
I live about 70km/40miles north of Melbourne, Victoria, Australia
and I still have a Landline Phone (which also handles my Internet
connection via a modem box near the phone socket).
As I understand it, the phone connection is Digital to the big box
in the street then analogue (copper line) to my home wall socket
(which is actually in the Master Bedroom).
Certainly, your broadband - if it comes via the same wire - will be
that: in UK we call that FTTC, fibre to the cabinet,
as opposed to full fibre to your home, FTTP (premises). It's quite
likely that your 'phone is similar - i. e. the ATA (analogue
telephone adapter) is in the street cabinet.
--I also have a mobile phone. ;-P
On Thu, 9/17/2026 6:25 AM, Daniel70 wrote:
Landline phones are hardly ever the old scheme any more.
A lot of the replacement schemes, you lose dial tone on a power outage.
And it's not "because your modem didn't have that battery", it's
provider infrastructure that doesn't have power during an outage. My
VOIP cannot work when the power goes off, because the box at the corner
runs off mains and has no battery.
And just yesterday, as an example of modern times, all the 911 service--
hosted by a telco, went out at the same time (likely a software update).
The police were telling people to phone a local number, a 123-456-7890
type number,
if there was an emergency. And in an emergency, isn't that the time you
"want to be doing research" ? It's good after the outage, to learn what
the number was that you were supposed to phone.
Quite a few people, when they drive off the road and have a smashup,
they reach for their smartphone... and there's no tower within reach.
It's one thing for the rural towers to have no emergency generator,
quite another for there to be no tower to make a call.
That's when you reach for that expensive SatPhone on your land yacht :-)
That always works.
Paul
| Sysop: | Amessyroom |
|---|---|
| Location: | Fayetteville, NC |
| Users: | 74 |
| Nodes: | 6 (0 / 6) |
| Uptime: | 121:07:43 |
| Calls: | 1,194 |
| Files: | 1,352 |
| Messages: | 290,208 |
