Docsis 2 question

Hello

i try run docsis 2 on ubr10k ( Version 12.3(23)BC6, RELEASE SOFTWARE (fc1)).
i configure interface as atdma

cable upstream 1 docsis-mode atdma
cable upstream 1 channel-width 6400000 6400000
cable upstream 1 minislot-size 2
cable upstream 1 power-level 4
cable upstream 1 range-backoff 3 6
cable upstream 1 modulation-profile 222

but modems show up registered as 1.1:
parnu_ubr10k#sh cable modem 10.19.0.176 phy
MAC Address I/F Sid USPwr USMER Timing DSPwr DSMER Mode DOCSIS
(dBmV) (SNR) Offset (dBmV) (SNR) Prov
(dB) (dB)
001e.696c.4970 C7/1/1/U1 2126 0.00 32.55 1433 0.00 ----- atdma 1.1
parnu_ubr10k#sh cable modem 10.19.0.176 mac
MAC Address MAC Prim Ver QoS Frag Concat PHS Priv DS US
State Sid Prov Saids Sids
001e.696c.4970 online 2126 DOC2.0 DOC1.1 yes yes yes 15 16


How to put modems work as D2?
and how i know D1.1 doesn' support channel-width 6400000. but modems are online on this D2 interface.
may be i don't understand something