Theoritical estimate based on line attenuation of 25.7 dB/Km (assuming the thickness of copper wire is 26 AWG (American Wire Gauge) or 0.405 milimetre diameter) -----This seems a low figure (Maybe its old VDSL) My NBN VDSL2 Profile 17a has a max bandwith of about 17MHz. We believe that BT may choose not to implement the wider profile. VDSL offers higher capacity than ADSL on short lines. Mais l'Arcep se montre prudente : selon l'Autorité, le débit réel observé serait plutôt de 80 mégabits par seconde. What is the theoretical db/Km at what frequency for new cable as I cant find it published anywhere. Le VDSL (Very high bit-rate DSL) est une évolution technologique de l’ADSL qui offre sur courte distance des débits supérieurs. Line Attenuation. Attenuation is a term used to describe the reduction of the adsl signal strength that occurs on the copper pair over distance and is measured in dB decibels. What I wanted was a simple chart so I could see if the signal to noise ratio and line attenuation values that my modem was reporting were good or bad. VDSL2 DSL Mode Fast Maximum Line rate 34.99 Mbps 62.03 Mbps Line Rate 6.4 Mbps 28 Mbps Data Transferred 1190.43 MBytes 1135.27 MBytes Output Power-4.1 dBm 12.9 dBm Line Attenuation 5.8, 30.2, 47.1 dB (up) 15.7, 39.2, 58.7 dB (down) Noise Margin 18.1 dB 22.1 dB I already have decent specifications for SNR so I … To operate successfully, VDSL equipment must overcome line attenuation, crosstalk, radio-frequency (RF) ingress and other interferences. Loop Att. It uses coaxial, fibre optic or twisted pair cable for short distances up to 4500 feet. Line Attenuation(dB): 29.1 90.3 102.3 13.7 N/A N/A N/A Signal Attenuation(dB): 29.1 N/A N/A 13.7 N/A N/A N/A Noise Margin(dB): 6.3 N/A N/A 7.1 N/A N/A N/A Of particular importance is operation on existing unshielded twisted-pair lines. Elle devient intéressante par rapport à la technologie ADSL2+, sur une distance inférieure à 1 km (1 000 mètres) du central téléphonique, ou noeud de raccordement abonnés (NRA). Needless to say green is good and red is bad. J'ai actuellement un BT Home Hub 5A avec un OpenWrt 18 pour mon accès VDSL. Measure of how much the signal has degraded between the DSLAM and the modem. Cordialement, mg36 Over the last 12 months my line attenuation is slowly increasing. Attenuation. Line attention is in relation to the "loop loss" on your line. Line attenuation (donc l'atténuation descendante) : 16,1 dB . A large part of what matters is the cable length, which your VDSL provider may or may not be able to provide. 20dB and below is outstanding; 20dB-30dB is excellent; 30dB-40dB is very good; 40dB-50dB is good; 50dB-60dB is poor and may experience connectivity issues; 60dB or above is bad … Sur VDSL, il y a un autre aspect, les interferences des paires adjacentes. I remember the attenuation sitting at 60.2db, now it has crept up to 61.4db, and i expect it to increase further. Basically it's the distance between you and the ISP and the quality of the copper to your house. VDSL Port Details Upstream Downstream Attainable Net Data Rate: 11920 kbps 53628 kbps Actual Aggregate Tx Power: 6.8 dBm 12.1 dBm ===== VDSL Band Status U0 U1 U2 U3 D1 D2 D3 Line Attenuation(dB): 5.8 30.8 46.4 N/A 14.5 38.3 59.5 To use it look up the values on your modem and see where they are on the chart. The lower this figure the better, and the better chance you have of getting the faster speeds. There are three layers in which the failure … Re: Understanding Noise Margin, Line Attenuation & Signal Attenuation it would seem an unlikely coincidence that at time you got free boost that 'normal' noise margin was dropped to 3db yes the test socket is where you describe and you do need a filter - filter same for adsl/vdsl - to conenct to test socket hen hub and phone to filter We figured it was just line conditions, we're about 1000m from the street cabinet but still think upstream could do better. The further you are away from the exchange the higher your attenuation figure will be as the signal loss increases. VDSL then installed with master splitter and line attenuation was then measured to be 22db with speed of around 18mb/s (seems to be inline with the distance from the local exchange) - after 2 months of use and latency spikes and chatting to a few knowledge people here, we opted to change to ADSL, expecting slightly lower speed but a more stable line. Κατηγορίες Τεχνολογία Ετικέτες ADSL, Line attenuation, Line noise, SNR margin, VDSL, VDSL2, Θόρυβος γραμμής Πλοήγηση άρθρων Προηγούμενο άρθρο Προηγούμενη Τι είναι στο σύμβολο σταυρός συν + με κύκλο στο κινητό σας I'm talking about things like Line Attenuation and Output Power. Things improve marginally but it looks like I'm out of luck for 50mbit. Comme son nom l'indique, le VDSL2 est le successeur du VDSL, un protocole de transmission qui booste les débits Internet sur les réseaux de paires de cuivre. Line 0: XTU-R (DS) XTU-C (US) Trellis: ON ON SRA: disabled disabled SRA count: 0 0 Bit swap: enabled enabled Bit swap count: 10 0 Line Attenuation: 9.3 dB 0.0 dB Signal Attenuation: 0.0 dB 0.0 dB Noise Margin: 44.7 dB 46.4 dB Attainable Rate: 109103 kbits/s 56616 kbits/s Actual Power: 12.0 dBm 6.6 dBm Per Band Status: D1 D2 D3 U0 U1 U2 U3 Hi there! So here are my demarc line stats. La technologie VDSL2 Very high speed Digital Subscriber Line 2) est un protocole de transmission de données sur une paire de cuivre, c'est à dire sur la boucle locale de France Télécom/Orange. Line attenuation is in relation to the "loop loss" on your line. Dans le cas d’un accès ADSL (Asymmetric Digital Subscriber Line), les débits proposés sont: • Un débit descendant en général de 1Mbit/s à 15Mbit/s. • Un débit montant en général inférieur à 1Mbit/s. VDSL2 est l'acronyme de Very high speed Digital Subscriber Line 2. il est clair qu'avec une marge au bruit de 3 dB, ce n'est vraiment pas bon surtout que tu as une erreur CRC, et comme annoncé par @JuanLucas38, le VDSL demande une desserte domestique parfaite . Tableau de comparaison; Définition; Différences Clés ; Conclusion; Tableau de comparaison. Please note that these are typical values and can often be affected by the particular conditions on your line, ... Firstly, adoption of the 30a VDSL2 profile (using a wide 30 MHz bandwidth) could deliver maximum speeds well above 100 Mbps, although this would mainly benefit premises located close to the street cabinet. Le VDSL2 (de l'anglais Very-high-bit-rate digital subscriber line 2) est un protocole de transmission de données à haut débit vers un abonné à travers une paire de fils de cuivre.VDSL2 est le successeur du VDSL.Parmi les améliorations notables, le débit maximal théorique passe de 34 à 100 Mbit/s en full-duplex, et la distance entre l'utilisateur et le DSLAM est portée à 3 500 mètres. As I couldn’t find such a chart anywhere I made one. They are (line attenuation): Download: 18.1, 49.3, 76.2 DB Upload: 4.2, 40.6, 58.2 DB Noise margin: Upload: 6.1 DB Download: 6.2 DB I found an attenuation to sync speed calculator for VDSL2, but due to my 3 figures for upload/download, I can’t work out how/where to put all these numbers in, to calculate the sync speed based on these attenuation figures. Any tech guys have a good answer ? The modulation method used in VDSL is DMT (Discrete Multitone Technique), which is the combination of QAM and FDM. Le VDSL 2 permettrait d'obtenir en théorie un débit descendant de 100 mégabits par seconde. Line Attenuation. Forum discussion: I would like to know a series of good VDSL line statistics. Les valeurs d'atténuation en Vdsl2 sont plus élevées qu'en Adsl et dépendent des fréquences utilisées. un peu … It also depends on the amount of users, who connect through the same copper. This document is very specific to VDSL service, though you can have either ADSL or VDSL service on the above mentioned routers and modules. Also i am still on 20cn adsl, with no planned date of any upgrade to 21cn. When referring to a band in the downstream direction, it is the measured difference in the total power transmitted by the xTU-C and the total power received by the xTU-R over all subcarriers of that band during initialization. Line Attenuation(dB): 27.7 89.4 102.3 8.9 68.6 64.7 N/A Signal Attenuation(dB): 27.7 N/A N/A 8.9 0.0 0.0 N/A Noise Margin(dB): 6.3 N/A N/A 5.4 N/A N/A N/A . Line attenuation. Les stats remontés sont : Line Mode: G.993.2 (VDSL2) Profile: 17a; Line Attenuation (LATN): 31.6 dB / 40.7 dB; Signal Attenuation (SATN): 26.4 dB / 40.0 dB; Noise Margin (SNR): 6.1 dB / 5.1 dB; Même si entre les atténuations estimées et le réel, il y a toujours une différence significative, je constate quand mê Here are my stats from my new VDSL … It explains how to troubleshoot VDSL related issues on the Cisco 880 Series, 890 Series, 860 Series, and VDSL/ Asynchronous Digital Subscriber Line (ADSL) Enhanced High Speed WAN interface cards (EHWICs). DSL signifie Digital Subscriber Line (ligne d'abonné numérique), qui transforme une ligne téléphonique ordinaire en une liaison de communication à large bande. It is IMPOSSIBLE to determine DSL sync speeds based on line of sight distance or street distance to your Node. Les débits asymétriques du VDSL 2 subissent des contraintes physiques identiques à celles du VDSL. It's also measured in dBs and you can check the number on your ADSL statistics page. is Line Attenuation. Non, 26.4 dB d'atténuation en Vdsl2, ce n'est pas énorme. I had been having line problems on ADSL, and have recently switched to 20MB VDSL, but it seems even less stable now. The closer you are to the ISP, typically the better speeds you can get. Attenuation and Noise margin are two important parameters which points to the line quality and intern the stability of the DSL connection Line Attenuation:€€ €€ 0.0 dB€€ €€€ €€ 0.0 dB Signal Attenuation:€€ €€ 0.0 dB€€ €€€ €€ 0.0 dB Noise Margin:€€ €€€ € 11.1 dB€€ €€€ €€ 6.0 dB Very High Bitrate Digital Subscriber Line (VDSL) technology is similar to ADSL with some enhancements. I guess attenuation is significantly different for ADSL and VDSL. Maximum signal loss recommendation is usually about 60dB. The lower the dB the better for this measurement. 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