Packet over SONet/SDH (POS) experience?

William Allen Simpson wsimpson at
Mon Oct 20 16:47:43 UTC 1997

> From: rja at (Ran Atkinson)
> To: nanog at, ietf-ppp at
> Cc: wsimpson at, pppsdh at
> On Oct 19  8:12, William Allen Simpson wrote:
> % Has anyone (that has deployed) been having incident reports?
> 	There are known operational incidents where an adversary sent
> an IP packet designed to set the SONET scrambling algorithm ["f(x)"]
> to all zeros.  This caused the SONET device to lose communications
> syncronisation and the circuit to go down, requiring a manual reset.
> Truly an ugly situation.
Please detail:
 - what dates?
 - which circuit paths?
 - which vendor equipment?
 - from whence we will derive, which vendor chipset?

> I've known about this issue ever since the PPP/SONET spec was
> published, but have withheld public comment until someone else
> mentioned the issue on a public list.
Too bad you were not involved in the discussion 3-5 years ago....

> PS: I'm not on the PPP or PPPSDH lists, so if folks on those lists
>   want me to see any followups, those folks will need to Cc: me
>   directly.
> PPS:  The followups list definitely will need trimming.  Please
>   edit appropriately if you followup...
Ran, the original did not have those followups, and I'm kind of annoyed
that you added them....  I really did _not_ need 4 copies, and I expect
that the other NANOG folks will be less than enthused as well!

WSimpson at
    Key fingerprint =  17 40 5E 67 15 6F 31 26  DD 0D B9 9B 6A 15 2C 32

More information about the NANOG mailing list