8
votes
Accepted
Is an ONT a modem?
Short answer: no, an ONT is no modem.
Modem is short for MOdulator/DEModulator and the term is only used for three device classes: telephone modems, DSL modems, and cable modems (thx Cody). These ...
- 82.7k
6
votes
Accepted
Does a dial-up modem support multiple users?
Almost all consumer Internet access links use only a single IP address and many business links as well. A single IP address can't be shared directly but extremely commonly (source) NAT is used.
A ...
- 82.7k
5
votes
What is a "rotary dialer" in the context of dialup connections?
In the 1990s in a British regional ISP, we had a choice from the telephone company of getting two settings for multiple lines:
In the ordinary hunt group, the next incoming call would arrive on the ...
- 16.2k
5
votes
What is a "rotary dialer" in the context of dialup connections?
From the HOWTO you linked:
rotary dial in set of telephone lines
When I wore a younger man's clothes, back in the late 1990ies, I ran a bunch of Shiva LAN Rovers (in their IBM guise labelled as ...
- 8,826
4
votes
Accepted
Can a VDSL2 to Ethernet converter be used as a replacement for a bridging VDSL2 modem?
The particular device you have listed is required to be used as a pair. This is for someone who want to extend a network across voice cabling, or for a small ISP to use to connect to customers. It ...
- 98.7k
4
votes
Accepted
What could cause kvm virtualized pfsense to get 84mbps behind physical pfsense, but then drop to 1mbps when it replaces physical pfsense?
JFL was correct it was a NIC checksum offloading error. My guess is that when my virtual router was behind my physical router it somehow made it so it didn't need to do checksumming.
Recap of ...
- 287
3
votes
CSU/DSU's and DSL modems
CSU/DSU is usually only used to refer to T-carrier lines, dubbed digital signal. T-carrier lines use Alternate Mark Inversion line codes. Basically, there are just two symbols - mark and space - at a ...
- 82.7k
3
votes
Are modems needed to connect routers?
Fundamentally a circuit is needed to convert the stream of data packets from the internal form used inside the device into a form suitable for tranmission over the physical medium in use.
Whether ...
- 13.2k
3
votes
Accepted
Are modems needed to connect routers?
Modems are only needed to translate signals between analog and digital circuits. Some devices called modems aren't really modems in the strictest sense. For instance, many variants of ethernet use ...
- 98.7k
3
votes
Why Business Class router don't usually include ADSL?
A DSL or DOCSIS modem is a specialized bridging device.
Including one in a router is either a cheap gimmick or increases the expense of a business device that will limit its adoption.
Spring for the ...
- 101
3
votes
Does a dial-up modem support multiple users?
In the 1980s, most of the dial-up connections I saw were UUCP, not IP. Our server would call the various other servers and exchange mail and files. In this way it most certainly was for more than ...
- 16.2k
2
votes
Accepted
Why Business Class router don't usually include ADSL?
Because "business class" implies use in many situations where the service may be supplied by something other than ADSL. Combined router/modems are pretty much a home/consumer niche device.
Getting ...
- 2,746
2
votes
Does a dial-up modem support multiple users?
The computer connected to the modem would start one PPP (or earlier, SLIP) session, and it would get one IP address from the ISP. So yes, one connection for every dial-up connection.
There were ...
- 2,416
2
votes
Accepted
Can all ports on nowadays switches act as uplink ports?
You can use any switch port as uplink (unless you've got a managed switch and the ports are configured differently).
Some early switches had a dedicated uplink port that was the only one capable of ...
- 82.7k
2
votes
Accepted
Can VPN on router connected to the modem bypass a double NAT created by two routers unbridged and connected to each other?
It depends on the type of VPN technology used and if IPSec is used for authentication and encryption and then what type of encryption and data integrity you use with IPSec. I know AH can bypass NATs ...
- 119
2
votes
Accepted
Modems involved in dial-up connection
Does this mean that, on either side of the connection (the home
network and the ISP), there is a modem involved? So the connection
goes from a modem at the home network, through the telephone line,...
- 98.7k
2
votes
Is an ONT a modem?
An ONT has some sort of modem inside, as the box people normally call a modem does. I mean, modem is short for modulator-demodulator, that is, something that takes a digital signal and modulates into ...
- 61
2
votes
EdgeRouterX not routing traffic
Please check configuration in edge router onces again . Configurations like interface configuration, routing ,ssh configuration ,Nating , make sure edge router egress interface connected to modem and ...
- 850
2
votes
How does the computer detect the routers Around?
Wireless access points transmit periodic beacon frames to announce the presence of wireless networks.
- 67.1k
2
votes
Accepted
Can 2 modems connected to the same router interfere with each other if their web access interface are the same IP address?
There's only a problem when they're on the same wire ("broadcast domain") -- but it won't stop either modem from working. And it's only a problem for you as you won't know which one will ...
- 31.8k
1
vote
How does the computer detect the routers Around?
WAPs send beacon frames to the STAs, and the STAs can send probe frames. This is all part of the 802.11 standard used by Wi-Fi.
Remember that the protocols you are referring to are layer-3 or above ...
- 98.7k
1
vote
Accepted
How are Upstream Frequencies assigned for Cable Modems?
Your cable modem receives configuration from the CMTS network. Generally, this is provisioned in their system based on your subscriber MAC address. That's why you have to let them know when you buy ...
- 5,449
1
vote
Modems involved in dial-up connection
Dial-up access over traditional phone lines is based on the same model as DSL
Umm no.
Dial-up access operates over the phone network. Your modem dials a phone number that connects to the ISP.
In ...
- 13.2k
1
vote
Is an ONT a modem?
So modem conceptually is generally used when you take a digital signal and apply a frequency modulation (pam or qam for example) that encodes multiple bits per symbol/signal. Optical modulations exist ...
- 31
1
vote
Accepted
Configuring Cisco ISR 1861 with External Cable Modem
ip route 0.0.0.0 0.0.0.0 FastEthernet0/0
ipv6 route ::/0 FastEthernet0/0
Never do that. That's proxy-arp. Too many people do that with zero clue what it actually means... that's not a dialup ...
- 31.8k
1
vote
Intermittent periods of high packet loss, one hop beyond router
Shielded cable does not perform as well as unshielded cable if it is not properly grounded, and the shield will actually create problems by reflecting internal signals back into the cable. Unshielded ...
- 98.7k
1
vote
Accepted
Modem configuration with many public ip
This is basic routing, a function that normally routers perform by default, without any special configuration other than setting the IP addresses on the interfaces.
Assuming the ISP take care of ...
- 19.5k
1
vote
Accepted
Modem/device that can connect and route calls depending on type?
Apparently, you are overthinking this.
With a PBX you get as many PSTN lines as necessary for the total number of simultaneous PSTN calls that you may have. Usually, you get a DID range that is ...
- 98.7k
1
vote
Specific web site traffic on 2 ISPs
You can do outbound routing to specific destination with static routes. You can prefer one of ISPs for particular site inbound with BGP and your own PI pool. You can do advanced routing decision with ...
- 1,133
1
vote
Are modems needed to connect routers?
A router transfers packets between two (or more) different networks. A typical case is a router sitting between the home or office network and the ISP's network. A more complex case might have several ...
- 111
Only top scored, non community-wiki answers of a minimum length are eligible