3GPP 24.501 v20.0.0 — the document's own text
9.11.4.28 Ethernet header compression configuration
Taught in 4. Inside TS 24.501, the document at the centre (CT1 — the group that writes what your phone says, overview).
The purpose of the Ethernet header compression configuration information element is to negotiate the use of EHC and the length of the CID field in the EHC packet (see 3GPP TS 38.323 [29]).
The Ethernet header compression configuration information element is coded as shown in figure 9.11.4.28.1 and table 9.11.4.28.1.
The Ethernet header compression configuration is a type 4 information element with the length of 3 octets.
| 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | |
|---|---|---|---|---|---|---|---|---|
| Ethernet header compression configuration IEI | octet 1 | |||||||
| Length of Ethernet header compression configuration contents | octet 2 | |||||||
| 0Spare | 0Spare | 0Spare | 0Spare | 0Spare | 0Spare | CID Length | octet 3 |
Figure 9.11.4.28.1: Ethernet header compression configuration information element
Table 9.11.4.28.1: Ethernet header compression configuration information element
| Length of CID field value (CID Length) (octet 3 bits 1 and 2) | ||
|---|---|---|
| Bit | ||
| 2 | 1 | |
| 0 | 0 | Ethernet header compression not used |
| 0 | 1 | 7 bits |
| 1 | 0 | 15 bits |
| All other values shall be interpreted as "7 bits".Bits 3 to 8 of octet 3 are spare and shall be coded as zero. |