Cm service vs rrc connect setup

[Mdaf]

Hello,
Whats the difference between cm service request and establishment cause sent on rrc request.
why would the ue send the sevice needed twices even if the cm service request is sent to core still the bts can send the establishment cause.
many thanks.

[peanut]

Dear,

The CM service request contains much more details than the RRC request

You could say the the RRC request is a header but the CM Service Request is the complete message

Best regards,

[shishio]

Direct Tunneling activated was to reduce the latency formely (Ping of RNC to SGSN & SGSN to GGSN)) now (Ping of RNC to GGSN) and improve throughput. It was discovered that this counter VS.IU.Sevice.Rejections increased after this activation. Hi what is the impact of this counter for wireless end?What services are affected by this?