I have a performance problem with 2 router (model 857) with a ADSL line (Provider IT-TELECOM - Alice FLAT).

If i change router with a home one (netgear, dlink, etc..) my line goes good (at least 4MBit with speedtest.net), if I use one of my cisco it slows down to 1.5MBit.

Configuration works normally without error but slow.

Here the references of one:

Model: Cisco 857 (MPC8272) processor (revision 0x400)
Board ID: FCZ1343C479
MPC8272 CPU Rev: Part Number 0xc, Mask Number 0x10
Configuration register is 0x2102
Chassis MAC Address: 0027.0dc8.77b8
Hardware revision: 4
Board Revision: A0
P/N: 74-3502-06
Top Assy P/N: 800-26778-07
Deviation Number: 0
Fab Version: 04
CLEI Code: VAMG710DRC
FRU: CISCO857-K9
Version Identifier: V06
Processor type: 95
Chassis S/N: FCZ1343C479
Radio Country Code: FFFF
Eeprom format version: 4
PCB S/N: F0C13414W3L
Firmware: IOS 12.4(15)T10 (c850-advsecurityk9-mz.124-15.T10.bin)
CP Express: Ver 1.3

Modem: Alcatel 20190
Vendor ID:         'STMI'        'IFTN'
Vendor specific:    0x0000        0x711A
Vendor country:        0x0F        0xB5
Chip ID:        C196 (0)
DFE BOM:        DFE3.0 Annex A (1)
Capacity used:        100%    45%
Noise Margin:        28.0 dB        27.0 dB
Output Power:        16.5 dBm    12.0 dBm
Attenuation:        41.0 dB        20.5 dB
Defect status:        None        None
Last fail code:        None
Watchdog counter:    0x27
Watchdog reset:        0
Selftest result:    0x00
Subfunction:        0x00
Interrupts:        49539 (0 spurious)
PHY Access Err:        0
Activations:        7
LED Status:        ON
LED on time:        100
LED off time:        100
Init FW:        init_AMR-3.0.014_no_bist.bin
Operation FW:        AMR-3.0.014.bin
FW Source:        embedded
FW Version:        3.0.14

Any help well be appreciate.

Alessio.