VSC7440 datasheet(133/444 Pages) MICROSEMI

133 / 444 page

Functional Descriptions

VMDS-10492 VSC7440 Datasheet Revision 4.2

116

Prior to each VCAP CLM lookup, the type of key to be used in the lookup is selected. A number of

parameters control the key type selection:

•

Configuration parameters (ADV_CL_CFG).

For each (port, VCAP CLM lookup) a key type can be specified for different frame types. Although

any key type can be specified for a given frame type, not all key types are in reality applicable to a

given frame type. The applicable key types are listed in the ANA_CL:PORT:ADV_CL_CFG register

description. The following frame types are supported:

•

IPv6 frames (EtherType 0x86DD and IP version 6)

•

IPv4 frames (EtherType 0x0800 and IP version 4)

•

MPLS unicast frames (EtherType 0x8847)

•

MPLS multicast frames (EtherType 0x8848)

•

MPLS label stack processing (frame type after MPLS link layer is processed)

•

Other frames (non-MPLS, non-IP)

•

The type of the current protocol layer. For each VCAP CLM lookup, a frame pointer can optionally be

moved to the next protocol layer, and the type of the next protocol layer can be specified. This

influences key type selection for the next VCAP CLM lookup. The variables frame_ptr and

frame_type holds information about the current protocol layer.

Key type specified in action in previous VCAP CLM lookup.

The action of a VCAP CLM lookup can optionally specify a specific key type to be used in the following

VCAP CLM lookup.

The full algorithm used for selecting VCAP CLM key type is shown in the following pseudo code.

// ======================================================================

// ANA_CL: VCAP CLM Key Type Selection

// Determine which key type to use in VCAP CLM lookup.

// The algorithm is run prior to each VCAP CLM lookup.

// ----------------------------------------------------------------------

// Frame position (byte pointer) for use as base for next VCAP CLM key

// Updated by UpdateFramePtrAndType() upon VCAP CLM lookup

int frame_ptr = 0;

// Frame type at frame_ptr position.

// Updated by UpdateFramePtrAndType() upon VCAP CLM lookup

// Supported values:

ETH:

frame_ptr points to DMAC

CW:

frame_ptr points to start of IP header or CW/ACH of MPLS frame

MPLS: frame_ptr points to an MPLS label.

frame_type_t frame_type = ETH;

int ClmKeyType(

// VCAP CLM index. 0=First VCAP CLM lookup, 5=Last lookup

clm_idx,

// Action from previous VCAP CLM lookup (if clm_idx > 0)

// clm_action.vld is only set if VCAP CLM lookup

// was enabled.

clm_action,

)

{

int

key_type = 0;

port_cfg_t port_clm_cfg;

port_clm_cfg = csr.port[port_num].adv_cl_cfg[clm_idx];

if (clm_action.vld && clm_action.nxt_key_type != 0) {

// Previous VCAP CLM lookup specifies next key type

VSC7440 датащи(PDF) 133 Page - Microsemi Corporation

VSC7440 датащи(HTML) 133 Page - Microsemi Corporation

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

датащи скачать

ссылки URL