In this article I talk about the TP-Link TD-W8960N – Modem ADSL2 + Wireless N Router 300Mbps. Despite being also a router, got the TP-Link TD-W8960N to use it exclusively as ADSL modem.
But why buy an ADSL modem if the provider already offers a? Explain: Not all modem are the same, the quality of the modem, actually, ADSL modem chipset, can ensure a few decibels on the relationship between signal and noise (SNR).
And why would I want an SNR greater? Also explain. When ADSL connection, my modem and the DSLAM to my provider will sync with the bandwidth set by my profile, which in your time is defined by the contracted bandwidth. But it is necessary that the SNR for that bandwidth is at an acceptable value (typically 12dB or more), otherwise modem and DSLAM will negotiate a lower bandwidth, you still stay within that acceptable value of SNR.
For example, I hired a plan of 10 Mbps. This means that the Live network will allow me a bandwidth of downstream of up to 10 Mbps. But so I can effectively reach such bandwidth the first link, that is the ADSL connection, synchronize with a bandwidth of downstream a little more than 10 Mbps (normally a little more 12 Mbps), otherwise it becomes a bottleneck and my connection never will reach the contracted bandwidth. The ADSL connection you need to have a slightly higher bandwidth to compensate for overloads of the protocols.
And what defines the SNR and bandwidth of the ADSL connection? Are several factors: profile, distance between the user's modem and the DSLAM, quality of the cabling used, and quality of chipsets the modem and the DSLAM are some of them. Let's discuss each one of them below.
The ADSL profile is defined by the provider. As I said, It typically is set to a value slightly higher than the contracted bandwidth. In the old days were fixed profiles, in other words, If there was any problem on line or modem to stay low SNR, the connection would be bad and fall, or would never fall, but lose many packages, requiring many retransmissions. Anyway, the contracted bandwidth would not be reached.
Today the most common is to use an Adaptive profile, so that modem and DSLAM will attempt to synchronize the bandwidth profile, Since the SNR will be at an acceptable level (Typically > 12dB). If this does not occur, DSLAM and modem negotiate a smaller bandwidth, that let the SNR with acceptable value. So the connection does not fall. But, the contracted bandwidth is not reached.
Note that the current version of ADSL is possible for DSLAM and modem change the bandwidth without having to disconnect and reconnect. Current modems typically support this function, but I've never seen a provider implements it, unfortunately.
And why decrease the bandwidth increases the SNR and increase the bandwidth decreases the SNR? Because contrary to popular belief the Socialists, There is no free lunch. If you want to transmit more data on the same physical medium, and that goes for any connection, not only ADSL, you need to transmit more bits in less time. For this you need to use a more aggressive encoding, which is more susceptible to noise, in other words, the SNR will be less. Another option is to use a higher frequency range, normally including highest frequencies that were not being used with less bandwidth. Higher frequencies attenuate with distance, which implies that are also more susceptible to noise, in other words, SNR smaller also.
In short, the more bandwidth, lower SNR. The great goal is to synchronize the bandwidth defined by the profile with a good SNR, But if it doesn't work, the modem will use less bandwidth to keep the SNR.
Distance between the user's Modem and the DSLAM
It is common knowledge that the further away you are from the telephone central, the shorter the bandwidths of the plans that you can hire. That's because the signal attenuates with distance, so the closer DSLAM, the higher your SNR and the greater the bandwidth that you can get.
The DSLAM is typically a building or phone carrier in a closet of those we found on the street. Cables are not always following the shortest route from the DSLAM to the user's home, but there's not much you can do about it. You will hardly convince the carrier to make the great path with the cables or even install a DSLAM near you.
So unless you want to move, There's not much to do here too.
Quality of the Cabling used
Good cables are shielded and more resistant to noise. The pairs are twisted, also to prevent the capture of noise. Again, There's not much that can be done with respect to cables that the operator uses. But you can improve the cables we use in our residence.
One drawback of the Alive, and possibly other mobile operators, do they not make the internal cabling. Many other providers are responsible for all the cabling inside the client's House. So with fiber optic and coaxial cable. But that's not the case of Alive with the telephone twisted pair.
Many times the customer has an old cabling and/or full of seams. Worth improving the internal cabling in order to win a few decibels in the SNR. Unfortunately the gains aren't always expressive, because the wiring inside the House of the client is typically only a small fraction of all cabling between the ADSL modem and the DSLAM.
Quality of ADSL Modem Chipsets and DSLAM
The quality of the chipset also makes a difference. A good chipset can take a few decibels more than SNR where it seemed impossible. On the DSLAM can't move and, again, you're not going to convince the carrier to exchange their equipment.
It is worth remembering that the Alive, and probably all the other carriers, don't invest more in ADSL. Investments are focused in optical fiber, but the expansions are slow, because in Brazil the infrastructure cost is too high and there is a lot of competition on behalf of cartels and bureaucracy. Then the ADSL infrastructure that exists today is the maximum that will be. Don't expect new DSLAM, because at most will switch equipment that give faulty.
And the ADSL modem? The ADSL modem is precisely the only variable in this equation that is within reach of the user. The provider gave you a? Ok, but you don't have to necessarily use it. You can install a modem best and benefit from it.
The motivation for the modem
I'm aware that a good ADSL modem can make all the difference. When I signed the first time ADSL, bought (at the time it would take to buy) a modem D-Link DSL-500 g. He answered right at the time, with my plan of 600 Kbps and after 1 Mbps. But when I changed to 2 Mbps started suffering with low SNR and linkage connection under 2 Mbps. My House was far from central and 2 Mbps was already close to the limit.
Lent so a modem D-Link DSL-500B for a friend to test and saw that made all the difference. With him it was possible to obtain higher SNR and consequently synchronize in approximately 2300 Kbps ADSL profile. I bought a DSL-500B and been happy for some time.
But after a few years the line was degrading. Claim with the carrier not resolve. I decided then to give a researched in the modem market and saw that the Belle of the ball was the Thomson TG-508v2 (if I remember correctly). I bought the pet and again gain occurred in SNR that allowed me to go back to try the contracted bandwidth.
Already in my current House, When I signed the ADSL Vivo gave me a modem better than these two D-Link and the Thomson, that is the DM2270 Datacom ADSL 2 ft + 2I – Askey RTA9211W (RTL8676) 2-Port ADSL. He picked up well for a long time, but eventually the internal cabling of the condo had trouble and I began to see my connection synchronize somewhat under 10 Mbps.
I complained and the condominium ended up passing a new cable, with a few more 20 pairs. But the end of that cable was a little further from my house than it was with the previous cable. With that used a longer excerpt of FE cable, It is also used by Alive between the distribution box and the client's House, General Custer, so a pattern for this last stretch. The FE cable is weather resistant, but it is a cord is braided or armored and, therefore, is quite susceptible to noise. With this ended up losing a little on SNR, with respect to the old cable before the defect, and I started to experiment with the range of synchronization 10 a 11 Mbps, below the 12 Mbps required to guarantee the contracted bandwidth.
It is worth remembering that the stretch of the little box to the before, General Custer, In addition to shorter, It was done with a shielded cable with 2 pairs (used for intercom and phone), what guarantee me a better signal. The path of the new cable is even shorter, but includes a few dozen cable FE metro, What explains the signal worse. On my part, Since the hiring of ADSL also modified the internal wiring, replacing a twisted pair that malfunctioned and had a cable splicing FE, that goes straight to the modem.
I could change again the internal wiring for a better cable. Could try to fight the condominium or afford out of pocket a better cable to replace the FE of the street. But I thought it would be cheaper and less stressful simply risking a new modem, give me the decibels more than I needed.
The choice of TP-Link TD-W8960N
Little has changed in the market of chipsets DSL in recent years. ADSL is a moribund pattern, that will eventually be completely replaced by optical fiber. In most civilized countries he practically doesn't exist anymore. There are exceptions, as Australia, where ADSL is still has a survival. Anyway the pattern no longer receives more updates and, Consequently, the chipsets are also a bit stagnant. In a way that is advantageous in choosing a modem, because there are chipsets have been tested enough and the community has already defined what are the best.
And the Belle of the ball are the chipsets from Broadcom. They provide the largest overall synchronization rate. Furthermore, Depending on the modem, They allow you to set a different target SNR 12 DB for synchronization. This value of 12 DB is defined taking into consideration the quality of the line swings. On my connection it is common to see the SNR swings up to 3dB down or up without synchronization lost. You can set a value less, as 6 DB or until 3 DB target, and be able to synchronize with larger bandwidths, even with a higher incidence of packages with errors, whose correction or retransmission is made automatically by the ADSL Protocol.
A short list of modems that use Broadcom chipset, Although a bit outdated, can be seen here. The whole list, only the TP-Link TD-W8960N is widely available in Brazil. Others have stopped being manufactured and/or are not found here.
The TP-Link TD-W8960N v7 uses BCM6318 chipset. Is a low-cost chipset, back to the third world (or “emerging markets” in Broadcom's own euphemism), but that meets your role well on ADSL synchronization. It is worth noting that the TP-Link often changes chipsets between different versions of a same model of hardware equipment. Previous versions of TP-Link TD-W8960N have used the BCM6358 and BCM6328. But with regard to ADSL, There should be no practical differences between them. Caution only with eventual changes to chipsets other manufacturers, that can also happen without the model number change.
The purchase of the TP-Link TD-W8960N
I bought the TP-Link TD-W8960N v7 by R$119,50 + R$ 20,90 de frete.
Check out some photos from the TP-Link TD-W8960N:
Installing and using the TP-Link TD-W8960N
The configuration of the TP-Link TD-W8960N It was very quiet, even I had to enter ADSL settings, because he has a number of providers, inclusive do Brasil, and just select to which the configuration is done automatically.
He was also in bridge mode (only modem) by default, so that I didn't even have to bother to turn off the part of his router.
The antennas are not removable in version 7. Initially they were, but in some hardware revisions to TP-Link decided to leave them to cut costs. So I couldn't remove them. Were just “Garnish”, Since I'm going to let the WiFi also turned off.
Once I've had some gain, with the SNR on 12,2 DB synchronization has occurred in 11.298 Kbps, What was more than I could with the modem of the Alive. The modem still indicates that we could reach 12.048 Kbps.
I decided to then change the target SNR to 6dB. With that I was able to sync with 7 DB in 12.412 Kbps, that is my profile. The modem indicates that in this configuration and line conditions I could reach 14.848 Kbps.
To change the target SNR, you need to log in via Telnet, using the same credentials in the web interface and use the command:
xdslctl configure --snr VALOR
where value can be set by following one of the tables below:
|VALUE||Change in target SNR|
|65500||– 9 dB|
|65450||– 12 dB|
|Current target SNR||SNR target||VALUE|
|6 dB||4,5 dB||75|
|6 dB||3 dB||50|
|9 dB||6 dB||50|
|9 dB||4,5 dB||25|
|9 dB||3,5 dB||1|
|12 dB||9 dB||50|
|12 dB||6,5 dB||1|
|12 dB||6 dB||65550|
|12 dB||4,5 dB||65525|
|12 dB||3 dB||65500|
|15 dB||12 dB||50|
|15 dB||9 dB||65550|
|15 dB||6 dB||65500|
|15 dB||4,5 dB||65475|
|15 dB||3 dB||65450|
|18 dB||15 dB||50|
|18 dB||12 dB||65550|
|18 dB||9 dB||65500|
|18 dB||6 dB||65450|
|18 dB||4,5 dB||65425|
|18 dB||3 dB||65400|
Lately I don't even have adjusted the target SNR, because I have got reasonable bandwidths in sync. At the time I write this article I got the modem synchronized in 12.181 Kbps and around 10,8 dB.
Anyway I always check, because the conditions are somewhat dynamic and eventually can happen in synchronization happen at a bad time and have a low bandwidth. In this case I do I login for Telnet and low SNR target to obtain a larger bandwidth.
You must change your modem?
At this point you may be wondering whether it is worth changing your carrier modem, whatever it is, for each chipset from Broadcom. The answer is: depends on.
Note the bandwidth with your modem to synchronize. Is a value of 20% a 30% above the contracted bandwidth? It's always the same value? If the answers are Yes, your modem is synchronizing the bandwidth profile and all is well. There is no need to change my modem, unless you are with other problems, as crashes. See also if the chipset the current modem is no longer one of Broadcom's recent, not to change six for half a dozen.
But if your modem is not Broadcom and is synchronizing with values that vary and are very close to or below the contracted speed. And if you ever contacted the carrier, ever changed internal wiring and nothing solved, so it may be worth investing in a better modem.
I can say that I am pleased with the TP-Link TD-W8960N – Modem ADSL2 + Wireless N Router 300Mbps, I bypassed my problem. Now the modem syncs with larger bandwidth and have no more problems with crashes as happened with the modem of the Alive. He has some weaknesses, as the interface sometimes does not load properly or does it take to load, cannot save the configuration of target SNR, not have HTTPS interface, ultimately… typical problems of TP-Link. It's probably a bad router, but as modem he can deliver very reasonable and better than the modem Vivo.