Information Technology Reference
In-Depth Information
DECnet Phase IV and ISO CLNS Addresses
Address conversion between DECnet Phase IV and ISO CLNS (Phase V) requires that NSAP addresses
be Phase IV compatible. If an address can be converted to a valid Phase IV address, it is Phase IV
compatible.
To be compatible, the OSI area number must be between 1 and 63 (when converted to decimal) and the
OSI station ID must be in the format AA00.0400.
xxxx
. In addition, the OSI area and the DECnet area
(calculated from the OSI station ID) must match. This allows the DECnet Phase IV address to be
extracted properly from the NSAP.
Table 11-8 shows addresses and their equivalent DECnet Phase IV addresses, and indicates whether the
NSAP address is Phase IV compatible and why.
Table11-8
OSI NSAP-to-DECnet Phase IV Address Conversion
DECnet
Address
(Decimal)
OSI
Area
OSI NSAP Address (Hex)
Phase-IV Compatible
49.1111.0012.AA00.0400.014
9.20
18
18.257
Yes
49.1111.0009.AA00.0400.BC0
4.20
9
1.188
No—OSI area does not match
the DECnet area
49.1111.0041.AA00.0400.FFF
F.20
65
63.1023
No—OSI area is greater than 63
49.1111.000E.AA00.0400.000
0.20
14
0.0
No—DECnet address in NSAP
station ID is invalid
49.1111.0009.0800.2B05.8297
.20
9
—
No—NSAP station ID is not in
the proper format
(AA00.0400.
xxxx
)
DECnet: Poor Performance
Symptom:
Performance in a DECnet network is slow or unreliable. Connections to hosts over one or
more routers are periodically inaccessible or drop unexpectedly.
