Broadband
Broadband Advanced Screen
Use the Advanced screen to enable or disable ADSL over PTM, Annex M, DSL PhyR, and SRA (Seamless Rate Adaptation) functions. The Zyxel Device supports the PhyR retransmission scheme. PhyR is a retransmission scheme designed to provide protection against noise on the DSL line. It improves voice, video and data transmission resilience by utilizing a retransmission buffer. It also lists ITU-T G.993.2 standard VDSL profiles you can comply with.
ITU-T G.993.2 standard defines a wide range of settings for various parameters, some of which are encompassed in profiles as shown in the next table.
*This features is not available on all models. See Overview for more information.
*If the settings in the screen are changed, the Zyxel Device will re-establish the DSL connections.
VDSL Profiles 
Profile
Bandwidth (MHz)
Number of downstream carriers
Carrier bandwidth (kHz)
Power (dBm)
Max. downstream throughput (Mbit/s)
8a
8.832
2048
4.3125
17.5
50
8b
8.832
2048
4.3125
20.5
50
8c
8.5
1972
4.3125
11.5
50
8d
8.832
2048
4.3125
14.5
50
12a
12
2783
4.3125
14.5
68
12b
12
2783
4.3125
14.5
68
17a
17.664
4096
4.3125
14.5
100
35a
30.000
3479
4.3125
14.5
100
35b
35.328
8192
4.3125
17.0
300
Click Network Setting > Broadband > Advanced to display the following screen.
Network Setting > Broadband > Advanced
The following table describes the labels in this screen.
Network Setting > Broadband > Advanced 
Label
Description
DSL Capabilities
PhyR US
Enable or disable PhyR US (upstream) for upstream transmission to the WAN. PhyR US should be enabled if data being transmitted upstream is sensitive to noise. However, enabling PhyR US can decrease the US line rate. Enabling or disabling PhyR will require the CPE to retrain. For PhyR to function, the DSLAM must also support PhyR and have it enabled.
PhyR DS
Enable or disable PhyR DS (downstream) for downstream transmission from the WAN. PhyR DS should be enabled if data being transmitted downstream is sensitive to noise. However, enabling PhyR DS can decrease the DS line rate. Enabling or disabling PhyR will require the CPE to retrain. For PhyR to function, the DSLAM must also support PhyR and have it enabled.
PhyR US/DS
Enable or disable PhyR US/DS (upstream/downstream) for both upstream and downstream transmission to the WAN. PhyR US should be enabled if data being transmitted upstream is sensitive to noise. However, enabling PhyR US can decrease the US line rate. Enabling or disabling PhyR will require the CPE to retrain. For PhyR to function, the DSLAM must also support PhyR and have it enabled.
Bitswap
Select Enable to allow the Zyxel Device to adapt to line changes when you are using G.dmt.
Bit-swapping is a way of keeping the line more stable by constantly monitoring and redistributing bits between channels.
SRA
Enable or disable Seamless Rate Adaption (SRA). Select Enable to have the Zyxel Device automatically adjust the connection’s data rate according to line conditions without interrupting service.
DSL Modulation
PTM over ADSL
Select Enable to use PTM over ADSL. Since PTM has less overhead than ATM, some ISPs use this for better performance.
G.Dmt
ITU G.992.1 (better known as G.dmt) is an ITU standard for ADSL using discrete multitone modulation. G.dmt full-rate ADSL expands the usable bandwidth of existing copper telephone lines, delivering high-speed data communications at rates up to 8 Mbit/s downstream and 1.3 Mbit/s upstream.
G.lite
ITU G.992.2 (better known as G.lite) is an ITU standard for ADSL using discrete multitone modulation. G.lite does not strictly require the use of DSL filters, but like all variants of ADSL generally functions better with splitters.
T1.413
ANSI T1.413 is a technical standard that defines the requirements for the single asymmetric digital subscriber line (ADSL) for the interface between the telecommunications network and the customer installation in terms of their interaction and electrical characteristics.
ADSL2
It optionally extends the capability of basic ADSL in data rates to 12 Mbit/s downstream and, depending on Annex version, up to 3.5 Mbit/s upstream (with a mandatory capability of ADSL2 transceivers of 8 Mbit/s downstream and 800 kbit/s upstream).
Annex L
Annex L is an optional specification in the ITU-T ADSL2 recommendation G.992.3 titled Specific requirements for a Reach Extended ADSL2 (READSL2) system operating in the frequency band above POTS, therefore it is often referred to as Reach Extended ADSL2 or READSL2.The main difference between this specification and commonly deployed Annex A is the maximum distance that can be used. The power of the lower frequencies used for transmitting data is boosted up to increase the reach of this signal up to 7 kilometers (23,000 ft).
ADSL2+
ADSL2+ extends the capability of basic ADSL by doubling the number of downstream channels. The data rates can be as high as 24 Mbit/s downstream and up to 1.4 Mbit/s upstream depending on the distance from the DSLAM to the customer's premises.
Annex M
Annex M is an optional specification in ITU-T recommendations G.992.3 (ADSL2) and G.992.5 (ADSL2+), also referred to as ADSL2 M and ADSL2+ M. This specification extends the capability of commonly deployed Annex A by more than doubling the number of upstream bits. The data rates can be as high as 12 or 24 Mbit/s downstream and 3 Mbit/s upstream depending on the distance from the DSLAM to the customer's premises.
Annex M/J
Annex M and Annex J are specified in ITU-T recommendations G.992.3 (ADSL2) and G.992.5 (ADSL2+). Annex M and Annex J enhance the capabilities of Annex A and Annex B by increasing the upstream transmission data rate, but slightly reduce the downstream data rates as a trade-off. Annex M supports data rates of up to 12 Mbit/s downstream and 3.5 Mbit/s upstream for ADSL2, and up to 24 Mbit/s downstream and 2.5 Mbit/s upstream for ADSL2+. Annex J supports data rates of up to 12 Mbit/s downstream and 3.5 Mbit/s upstream for ADSL2, and up to 24 Mbit/s downstream and 3.5 Mbit/s upstream for ADSL2+. However, the actual downstream/upstream data rates depend on the distance from the ISP DSLAM to the Zyxel Device and the quality of your telephone line. Click the switch to enable the Zyxel Device to use Annex M for Zyxel Device models that use POTS WAN connection, and use Annex J for Zyxel Device models that use ISDN WAN connection.
VDSL2
VDSL2 (Very High Speed Digital Subscriber Line 2) is the second generation of the VDSL standard (which is currently denoted VDSL1). VDSL2 allows a frequency band of up to 30MHz and transmission rates of up to 100 Mbps in each direction. VDSL2 is defined in G.993.2.
VDSL Profile
VDSL2 profiles differ in the width of the frequency band used to transmit the broadband signal. Profiles that use a wider frequency band can deliver higher maximum speeds.
8a, 8b, 8c, 8d, 12a, 12b, 17a, 30a, 35b US0
The G.993.2 VDSL standard defines a wide range of profiles that can be used in different VDSL deployment settings, such as in a central office, a street cabinet or a building.
The Zyxel Device must comply with at least one profile specified in G.993.2. but compliance with more than one profile is allowed.
Cancel
Click Cancel to return to the previous configuration.
Apply
Click Apply to save your changes back to the Zyxel Device.