DSL-Speed Fritz 7520

Installing and Using OpenWrt
1

Hello, I've installed OpenWrt on a Fritz!Box 7520 and am experimenting with it a bit. Normally, I use a Fritz!Box 7490 with the original Fritz!OS. I measured about 57.000 Mb/s on my DSL connection with the 7490 running Fritz!OS using nperf. On the Fritz!Box 7520 with OpenWrt 24.10.5, I'm only getting about 36.000 Mb/s. What could be the reason for this? Theoretically, the 7520's hardware is even newer. Are the drivers not optimal for it?

the 7490 shows: VDSL2 17a G.Vector (ITU G993.5)

the 7520 shows: G993.2 VDSL2 Profile 17a

2

Make sure that you have a correct xDSL firmware installed.
Keep in mind that ASSIA (if you are on the Telekom network) will penalize playing with the modem, any modem changes or reboots. It can take 10-14 days to fully recover.

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3

Okay, after switching back to the 7490 with Fritz!OS, the speed was back to 57.000 Mb/s. Wouldn't that indicate a restriction by ASSIA or DLM?
Is there a better firmware version than the one included in version owrt 24.10.5 for the Fritz!Box 7520 by default?

4

Mine shows the following with modem firmware from a Draytek Vigor 2765. Stock firmware on 7590s was in the same range.

**Line State:**Showtime with TC-Layer sync
**Line Mode:**G.993.2 (VDSL2, Profile 17a, with down- and upstream vectoring)
**Data Rate:**109.999 Mb/s / 31.397 Mb/s
**Noise Margin:**6.4 dB / 6.3 dB

config dsl 'dsl'
#       option mtu '2002'
        option annex 'b'
        option line_mode 'vdsl'
        option xfer_mode 'ptm'
#       option tone 'bv'
#       option firmware '/lib/firmware/xcpe_8.D.1.9.1.7_8.D.0.C.1.1.bin' # 17a auf VC-231 und 30a/high auf ALL-MC115VDSL2
#       option firmware '/lib/firmware/xcpe_8.D.1.9.1.7_8.D.0.C.1.2.bin'
#       option firmware '/lib/firmware/xcpe_8.D.1.F.1.7_8.D.1.0.1.1.bin' # 17a auf VC-231 und 30a/high auf ALL-MC115VDSL2
        option firmware '/lib/firmware/xcpe_8.D.1.F.1.7_8.D.1.0.1.2.bin'
        option ipv6 '0'

got it via https://github.com/xdarklight/lantiq-xdsl-firmware-info/issues/35

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5

You will probably notice an increase if you try a different vdsl firmware file

You can extract newer blobs from Fritz or Draytek firmware.

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6

That sounds encouraging, but it's probably too complicated for me to install. The article on GitHub is also quite old. Is it possible that the software isn't already integrated into version 24.10.5?
Oddly enough, I experimented with OWRT a few months ago. I didn't notice any such significant speed differences then.

7

Using the extracted firmware seems like the most sensible approach. I'll try it. Thanks.

8

the .all file from github should be renamed and replaced with the existing .bin file in /lib/firmware? Unfortunately, that doesn't work. Have I misunderstood something?

9

Do I need to use the firmware for a VRX518 with the 7520? Is it integrated into the kernel of the Fritz!Box firmware and cannot be extracted?

10

the .all file contains multiple .bin files that can be extracted with these python scripts

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11

Thanks for your efforts to help me, but unfortunately I can't manage it this way. Could someone perhaps be kind enough to provide me with the extracted files for a Fritz!Box 7520 with an IPQ4019 chip and VRX518? Maybe someone will take pity on a noob like me, perhaps even via private message.

12

perhaps this post might help understand the process.

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13

Thanks for the helpful answers. I think I've solved it and tested the firmware xcpe_563716_561111.bin from the Vogor2765. The speed is similar to the xcpe_8D1507_8D0901.bin included in the default firmware. What else could be causing the speed to be so much lower than with my old 7490 running Fritz!OS?

14

Correction, unfortunately it didn't work at all. Yesterday I replaced the file xcpe_8D1507_8D0901.bin and then restarted dsl_control in luci. I've since completely rebooted the box, but it won't start anymore. A failsafe reset was necessary. I suspect I did everything wrong. Is only replacing the xcpe...bin file necessary, or do I need another one as well?

15

Maybe your firmware file is bad, and the service restart didn't actually load it. It is always a good idea to check from the command line using ubus call dsl metrics which firmware is actually running.

You could try the version from the original Fritzbox firmware: First, unpack the firmware image (it is just a tar archive). Then extract "filesystem.image", ideally using unsquashfs, but alternatively 7z also works (it dumps everything in the same folder instead of the proper directory structure though). The firmware image is "vr11-B-dsl.bin" in "/lib/modules/dsp_vr11".

Aside from that: Instead of replacing the firmware file, it is probably better to put it somewhere else, and change the DSL config to point to it.

As an example, you could create a new directory "/etc/dsl/" and put it there. If you add the path to "/etc/sysupgrade.conf", the firmware will also be preserved during system upgrades.

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16

Hi @janh, thank you so much. Now I understand. That worked quickly. I'm now using the firmware from the latest Fritz-OS 7520-08.21: "8.13.1.10.1.7". The owrt firmware included "8.13.1.5.0.7". With both the data rate is roughly the same and significantly lower than with my old Fritz 7490. Would it make sense to look for an older firmware version from Fritz? Or are there other parameters I could adjust to improve things?

17

Ok, but how are the negotiated data rates?

Could you post something similar to the above quoted?

18

Yes, of course, the values ​​were very similar immediately before the swap.

Line State: Showtime with TC-Layer sync
Line Mode: G.993.2 (VDSL2, Profile 17a, with down- and upstream vectoring)
Data Rate: 44.991 Mb/s / 19.999 Mb/s
Noise Margin: 9.4 dB / 6.8 dB

19

I guess, these're the values for the 7520?
And the negotiated data rates for the 7490 were better?

20

Yes, according to the Fritz!Box GUI, the 7490's values ​​were last around 63,000 Mbps. But I measured with nperf, and the actual speed was a bit lower. The difference between Fritz!Box and OWRT was always around at 70%.