Interface Configuration Guide 7705 SAR Interfaces
Edition: 01 3HE 11011 AAAC TQZZA 69
Once MLPPP has been successfully negotiated, the sending system is free to send
PDUs encapsulated and/or fragmented with the MP header.
MP introduces a new protocol type with a protocol ID (PID) of 0x003d. Figure 2 and
Figure 3 show the MLPPP fragment frame structure. Framing to indicate the
beginning and end of the encapsulation is the same as that used by PPP and
described in RFC 1662, PPP in HDLC-like Framing.
MP frames use the same HDLC address and control pair value as PPP: Address –
0xFF and Control – 0x03. The 2-octet protocol field is also structured the same way
as in PPP encapsulation.
Figure 2 MLPPP 24-bit Fragment Format
Figure 3 MLPPP 12-bit Fragment Format
The required and default format for MP is the 24-bit format. During the LCP state, the
12-bit format can be negotiated. The 7705 SAR is capable of supporting and
negotiating the alternate 12-bit frame format.
The maximum differential delay supported for MLPPP is 25 ms.
01234567890123456789012345678901
1111111111222222222233
Address 0xff
BE
Control 0x03 PID 0x003d
Sequence
Fragment Data...
Fragment Data... FCS
19487
01234567890123456789012345678901
1111111111222222222233
Address 0xff
BE
Control 0x03 PID 0x003d
Sequence Fragment Data
Fragment Data...
Fragment Data... FCS
19488
To Next Page
Loading...
