[nsp] Ethernet/G.703 converter & Cisco G.703 interface

[sthaug at nethelp.no]

> This could be the Cisco-HDLC header.  Or something else prepended by 
> the "Cisco half-bridge" to the packets.

It looks like Cisco HDLC. From

	http://www.nethelp.no/net/cisco-hdlc.txt

| The first ("address") octet is set to 0x0F for unicast packets and 0x8F
| for broadcast packets. Broadcast just means that the higher-level protocol
| thought this was a broadcast packet; cisco doesn't support multidrop
| HDLC at this time.
| 
| The second ("control") octet is always 0.
| 
| The next two octets are a 16-bit protocol code, sent most-significant-first.
| These codes are usually Ethernet type codes. cisco has added some codes to
| support packet types that don't appear on Ethernets. The current list of codes
| is as follows:
...
| TYPE_BRIDGE             0x6558  Bridged Ethernet/802.3 packet

Steinar Haug, Nethelp consulting, sthaug at nethelp.no