Vdsl Features Supported By The Ar1200 - Huawei AR1200 series Configuration Manual

Huawei AR1200 Series Enterprise Routers
Configuration Guide - Interface Management
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Both VDSL and ADSL can provide Internet browsing, email receiving and sending, file upload
and download, working at home, remote education, and remote shopping. VDSL meets
requirements of users for high-speed access, makes full use of existing twisted-pair telephone
lines, protects carrier investments, and solves the bottleneck of the last mile.

13.2 VDSL Features Supported by the AR1200

To enable the AR1200 function as a CPE to transmit services on an VDSL line, deactivate an
VDSL interface on the AR1200, set parameters for the interface, and then activate the interface
to make configurations take effect.
Interface Activation
Activation of a VDSL interface refers to the training between a DSLAM and a CPE. During the
training, the two devices check the line distance and status and negotiate parameters such as the
transmission standard, upstream and downstream line rates, and specified noise margin. If the
training succeeds, the VDSL interface on the CPE is activated and can transmit data.
After an AR1200 starts, its VDSL interface is automatically activated. The VDSL interface
remains activated as long as its VDSL line works properly. To set line parameters, deactivate
the VDSL interface on the CPE. After setting parameters, activate the interface to make
configurations take effect.
Working Mode
An AR1200 supports two working modes for VDSL interfaces:
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upstream transmission rate of 0.8 Mbit/s to 6.4 Mbit/s and the downstream transmission
rate of 6.5 kbit/s to 52 Mbit/s. In the last mile, VDSL provides 10 Mbit/s upstream and
downstream transmission rates. VDSL transmits services faster than ADSL.
Line activation rate: ADSL provides high transmit power, so lines interfere with each other.
ADSL provides the line activation rate of only 10% to 30%. VDSL provides low transmit
power, so there is less crosstalk. VDSL provides the line activation rate of over 90%.
Transmission mode: ADSL provides only asymmetrical transmission, but VDSL provides
both asymmetrical and symmetrical transmission.
Frequency band: ADSL transmits digital signals at the frequency bands of 25 kHz to 1.1
MHz, but VDSL uses higher frequency bands of 0.138 MHz to 12 MHz.
Transmission quality: VDSL provides good transmission quality and supports HD video
conference, VoD, and BTV, whereas ADSL cannot provide these services.
Deployment cost: VDSL transmits signals over a copper twisted pair without layout new
lines or reconstructing the existing network.
Service compatibility: Compared with ADSL, VDSL supports both traditional voice
services and ISDN services. VDSL can use the same phone line with the existing phone
line and ISDN.
Asynchronous Transfer Mode (ATM): ATM cells are transmitted over VDSL lines.
Packet Transfer Mode (PTM): Ethernet frames are transmitted over VDSL lines.
Ethernet frames do not need to be fragmented into ATM cells. 1483B/1483R encapsulation,
ATM Adaptation Layer 5 (AAL5) encapsulation, and ATM cell encapsulation are not
required, enabling Ethernet services to be transmitted more rapidly than in ATM mode.
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