getting upstream 'if index' assigned to a cable modem

Hello,

Recently I am facing an issue regarding allocation of upstreams to cable modems in cisco CMTS products.

Actually we can get the upstream assigned to a cable modem from 1.3.6.1.2.1.10.127.1.3.3.1.5 i.e., from 'docsIfCmtsCmStatusUpChannelIfIndex' column in 'docsIfCmtsCmStatusTable'. But these days I am getting response only to docsis2.0 version cable modems from '1.3.6.1.2.1.10.127.1.3.3.1.5' . I am not getting response to docsis3.0 cable modems.

How can I get upstream index allocated to docsis3.0 cablemodems ?

Thanks in advance