Setting this object to 'true' enables the loopback
function. Setting this object to 'false' disables the
loopback function. When enabled, the eCM removes the
Ethernet FCS/CRC32 from the original packets. All Ethernet
packets received by the SLED from the LCI are then processed
as follows:
1. If the received Ethernet packet is greater than 1472
octets, the Ethernet packet is split into two fragments,
the first consisting of the first 1472 octets of the
Ethernet packet and the second containing the remaining
octets, resulting in two payloads that are processed as
described below. If the received Ethernet packet is less
than or equal to 1472 octets, the entire packet will be
processed as a single payload.
2. For each payload generated in step 1, the payload is
appended to the contents of sledLoopbackPktHdr.
3. The mutable fields within sledLoopbackPktHdr MUST be
recomputed. The mutable fields are IP Header Checksum, IP
Total Length, UDP Checksum, and UDP Length.
4. If the Ethernet packet was fragmented in step 1, the
appropriate IP header fields (Flags and Fragment Offset)
are updated to indicate IP fragmentation These IP
fragmentation header values will differ depending on
if this is the first or second fragment being processed.
5. The Ethernet FCS is computed and appended.
6. The resulting Ethernet packet is transmitted to the
LCI.
Parsed from file SLED-MIB.mib
Module: SLED-MIB
Vendor: Cable Television Laboratories, Inc.
Module: SLED-MIB
[Automatically extracted from oidview.com]
sledLoopbackEnable OBJECT-TYPE SYNTAX TruthValue MAX-ACCESS read-write STATUS current DESCRIPTION "Setting this object to 'true' enables the loopback function. Setting this object to 'false' disables the loopback function. When enabled, the eCM removes the Ethernet FCS/CRC32 from the original packets. All Ethernet packets received by the SLED from the LCI are then processed as follows: 1. If the received Ethernet packet is greater than 1472 octets, the Ethernet packet is split into two fragments, the first consisting of the first 1472 octets of the Ethernet packet and the second containing the remaining octets, resulting in two payloads that are processed as described below. If the received Ethernet packet is less than or equal to 1472 octets, the entire packet will be processed as a single payload. 2. For each payload generated in step 1, the payload is appended to the contents of sledLoopbackPktHdr. 3. The mutable fields within sledLoopbackPktHdr MUST be recomputed. The mutable fields are IP Header Checksum, IP Total Length, UDP Checksum, and UDP Length. 4. If the Ethernet packet was fragmented in step 1, the appropriate IP header fields (Flags and Fragment Offset) are updated to indicate IP fragmentation These IP fragmentation header values will differ depending on if this is the first or second fragment being processed. 5. The Ethernet FCS is computed and appended. 6. The resulting Ethernet packet is transmitted to the LCI." DEFVAL { false } ::= { sledLoopback 2 }
| OID | Name | Sub children | Sub Nodes Total | Description |
|---|---|---|---|---|
| 1.3.6.1.4.1.4491.2.1.13.1.2.1 | sledLoopbackInterface | 0 | 0 | The index of the logical CPE interface (LCI) that the SLED loopback function is attached to. If the index does not correspond to… |
| 1.3.6.1.4.1.4491.2.1.13.1.2.3 | sledLoopbackPktHdr | 0 | 0 | A properly formatted Ethernet(DIX)+IP+UDP headers for use in SLED loopback processing as described in sledLoopbackEnable. The obj… |