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| Title: | FDDI - The Next Generation |
|
| Moderator: | NETCAD::STEFANI |
|
| Created: | Thu Apr 27 1989 |
| Last Modified: | Thu Jun 05 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 2259 |
| Total number of notes: | 8590 |
479.0. "SDA and performance questions" by CSC32::D_MILLER () Tue Feb 18 1992 18:50
Hello,
I have several questions.
1) The MDF release notes state that the TTRT (target token rotation time)
must be less that 8ms. When looking at FXA0 in SDA, the "negotiated TRT"
shows 99840. Is this the token rotation time? What unit is this field in
and is this out of spec? What should it be?
The command is:
SDA>SHOW LAN/DEVICE=FXA
2) Using the same command as above, the upstream neighbor has an
address of 00000000. Why do we not get a valid address?
3) Is SDA>SHOW LAN/DEVICE=FXA a supported command?
4) Any tips on troubleshooting FDDI performance issues?
SDA> SHOW LAN/DEVICE=FXA
LAN Data Structures
-------------------
-- FXA Device Information 18-FEB-1992 15:22:45 --
LSB address 80739B10 Active unit count 7
LAN version 00000001 05050015 Driver version 00000005 05043016
LAN code address 80734514 Driver code address 807314F4
Device name FX_DEMFA Device type 43
Device version 00000000 00000000 DLL type FDDI
Data chaining ON All multicast state OFF
Controller mode NORMAL Promiscuous mode OFF
CRC generation mode ON Hardware mode 0000
Physical address 08-00-2B-24-FD-04 Hardware address 08-00-2B-24-FD-04
Flags: 0000 Characteristics: 0001 Devctr
Status: 4013 Inited,Run,Timer
DAT stage 00000000 DAT xmt status 00000021 00210001
DAT number started 2 DAT xmt complete 13-FEB 11:30:37
DAT number failed 0 DAT rcv found None
Press RETURN for more.
SDA>
LAN Data Structures
-------------------
-- FXA Device Information (cont) 18-FEB-1992 15:22:45 --
Creation time None Create count 0
Deletion time None Enable count 0
Enabled time None Fatal error count 0
Disabled time None Excessive collisons 0
Last receive 18-FEB 15:22:45 Last fatal error None
Last transmit 18-FEB 15:22:45 Prev fatal error None
Last fork sched 18-FEB 15:22:45 Last exc collision None
Last fork time 18-FEB 15:22:45
Rcv buffers owned by device 31 System buffer quota 0
Xmt entries owned by device 1 Device dependent longword 00000000
Xmt entries owned by host 0 # restarts pending 0
NMgmt advised buffer count 0 Events logged 0
EIB address 00000000 NMgmt assigned adr 00-00-00-00-00-00
LPB address 00000000
Press RETURN for more.
SDA>
LAN Data Structures
-------------------
-- FXA Queue Information 18-FEB-1992 15:22:45 --
Control hold queue 80739C18 Status: Valid, empty
Control request queue 80739C20 Status: Valid, empty
Control pending queue 80739C28 Status: Valid, empty
Transmit request queue 80739C10 Status: Valid, empty
Transmit pending queue 80739C30 Status: Valid, empty
Receive buffer queue 80739C38 Status: Valid, 1 element
Receive pending queue 80739C40 Status: Valid, 31 elements
Post process queue 80739C48 Status: Valid, empty
Delay queue 80739C50 Status: Valid, empty
Auto restart queue 80739C58 Status: Valid, empty
Netwrk mgmt hold queue 80739C60 Status: Valid, empty
-- FXA Multicast Address Information 18-FEB-1992 15:22:45 --
None
Press RETURN for more.
SDA>
LAN Data Structures
-------------------
-- FXA FDDI Information 18-FEB-1992 15:22:45 --
Data link arch version 00000101 Module serial num 53413030
Max token rotation time 2162688 Module serial num 30393131
Negotiated TRT 99840 Module serial num 34363031
Valid transmission time 32768 Upstream neighbor 00-00-00-00-00-00
LEM threshold 8 Phy state 7
Port type 4195311 Link state 4
DAT results 0 Ring purger state 0
FDDI flags: 0000
Press RETURN for more.
SDA>
LAN Data Structures
-------------------
-- FXA Unit Summary 18-FEB-1992 15:22:56 --
UCB UCB Addr Fmt Value Client State
--- -------- --- ----- ------ -----------
FXA0 80727A50
FXA1 807280E0 Eth 60-07 SCA 0017 Strtn,Len,Uniq,Strtd
FXA2 80879660 Eth 60-03 DECNET 0017 Strtn,Len,Uniq,Strtd
FXA3 80764D70 802E 08-00-2B-80-3E DTIME 0015 Strtn,Uniq,Strtd
FXA4 8075D2F0 Eth 60-04 LAT 0015 Strtn,Uniq,Strtd
FXA5 8076EDC0 Eth 80-3C DNAME 0017 Strtn,Len,Uniq,Strtd
FXA66 8076E020 Eth 60-01 MOPDL 001F Strtn,Len,Uniq,Share,Strtd
FXA67 8076E540 Eth 90-00 LOOP 001D Strtn,Uniq,Share,Strtd
Press RETURN for more.
SDA>
LAN Data Structures
-------------------
-- FXA Counters Information 18-FEB-1992 15:22:58 --
Seconds since zeroed 446206 Station failures 0
Octets received 250208656 Octets sent 169175542
PDUs received 1465172 PDUs sent 1000372
Mcast octets received 100032268 Mcast octets sent 10681458
Mcast PDUs received 478810 Mcast PDUs sent 77968
Unrec indiv dest PDUs 1 PDUs sent, deferred 0
Unrec mcast dest PDUs 0 PDUs sent, one coll 0
Data overruns 0 PDUs sent, mul coll 0
Unavail station buffs 0 Excessive collisions 0
Unavail user buffers 0 Carrier check failure 0
Frame check errors 0 Short circuit failure 0
Alignment errors 0 Open circuit failure 0
Frames too long 0 Transmits too long 0
Rcv data length error 0 Late collisions 0
802E PDUs received 5039 Coll detect chk fail 0
802 PDUs received 0 Send data length err 0
Eth PDUs received 5152284 Frame size errors 0
Press RETURN for more.
SDA>
LAN Data Structures
-------------------
-- FXA FDDI Counters Information 18-FEB-1992 15:22:58 --
Transmit underrun 0 Dup tokens detected 0
Transmit failure 0 Ring purge errors 0
Frame status error 0 FCI strip errors 0
Frame length error 0 Traces initiated 0
MAC frame count 8422819749 Traces received 0
MAC error count 0 Directed beacons rcvd 0
MAC lost count 0 Elasticity buffer err 0
Ring inits initiated 0 LCT rejects 0
Ring inits received 0 LEM rejects 0
Ring beacon initiated 0 Link errors 0
Dup add test failures 0 Connections completed 1
Press RETURN for more.
SDA>
LAN Data Structures
-------------------
-- FXA Internal Counters Information 18-FEB-1992 15:22:58 --
Internal counters address 8073ACF6 Internal counters size 62
Number of ports 0 Global page transmits 0
No work transmits 862 SVAPTE/BOFF transmits 0
Bad PTE transmits 0 Buffer_Adr transmits 0
Fatal error count 0 RDL errors 0
Transmit timeouts 0 Last fatal error None
Restart failures 0 Prev fatal error None
Power failures 0 Last error CSR 00000000
Hardware errors 0 Fatal error code None
Control timeouts 0 Prev fatal error None
Loopback sent 0 Loopback failures 0
System ID sent 0 System ID failures 0
ReqCounters sent 0 ReqCounters failures 0
Press RETURN for more.
SDA>
LAN Data Structures
-------------------
-- FXA0 Template Unit Information 18-FEB-1992 15:23:14 --
LSB address 80739B10 VCIB address 00000000
Packet format Ethernet Error count 0
Device buffer size 1500 LAN medium FDDI
Maximum buffer size 1500 Eth protocol type 00-00
Hardware buffer quota 32 802E protocol ID 00-00-00-00-00
Receive buffer quota 0 802.2 SAP 00
Allow prom client ON 802.2 Group SAPs 00,00,00,00
Promiscuous mode OFF Maximum header size 0
802.2 service OFF Hardware address 08-00-2B-24-FD-04
Data chaining OFF Physical address FF-FF-FF-FF-FF-FF
Padding mode ON Can change address OFF
Automatic restart OFF Access mode EXCLUSIVE
CRC generation mode ON Controller mode NORMAL
Maintenance state ON Rcv buffs to queue 1
P2 parameters 00000000 Starter's PID 00000000
All multicast mode OFF Creator's PID 00000000
Rcv buffer quota 0 LSB size 4650
Press RETURN for more.
SDA>
LAN Data Structures
-------------------
-- FXA1 60-07 (SCA) Unit Information 18-FEB-1992 15:23:15 --
LSB address 80739B10 VCIB address 80BA9578
Packet format Ethernet Error count 0
Device buffer size 1500 LAN medium FDDI
Maximum buffer size 4468 Eth protocol type 60-07
Hardware buffer quota 32 802E protocol ID 00-00-00-60-07
Receive buffer quota 0 802.2 SAP 00
Allow prom client ON 802.2 Group SAPs 00,00,00,00
Promiscuous mode OFF Maximum header size 26
802.2 service OFF Hardware address 08-00-2B-24-FD-04
Data chaining OFF Physical address 08-00-2B-24-FD-04
Padding mode ON Can change address ON
Automatic restart ON Access mode EXCLUSIVE
CRC generation mode ON Controller mode NORMAL
Maintenance state ON Rcv buffs to queue 1
P2 parameters 0C7341B3 Starter's PID 00000000
All multicast mode OFF Creator's PID 00000000
Rcv buffer quota 0 LSB size 4650
Press RETURN for more.
SDA>
LAN Data Structures
-------------------
-- FXA1 60-07 (SCA) Counters & Misc Info 18-FEB-1992 15:23:15 --
Last receive 18-FEB 15:23:15 Last transmit 18-FEB 15:23:15
Octets received 498146883 Octets sent 577816273
PDUs received 3856787 PDUs sent 3088649
Mcast octets received 0 Mcast octets sent 0
Mcast PDUs received 0 Mcast PDUs sent 0
Unavail user buffer 0 Last start attempt None
Last start done 13-FEB 11:26:09 Last start failed None
Share UCB total quota 0
Receive IRP queue 807282A4 Status: Valid, empty
Shared users queue 80728294 Status: Valid, empty
Receive pending queue 8072829C Status: Valid, empty
-- FXA1 60-07 (SCA) Multicast Address Info 18-FEB-1992 15:23:15 --
Multicast address table, embedded:
AB-00-04-01-E3-F3
Any help would ge greatly appreciated.
Thanks,
Danny Miller
| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 479.1 | Ethernet packets on FDDI???!!! | STKHLM::WEBJORN | Gullik Webj�rn Product & Technology Group | Wed Feb 19 1992 08:52 | 11 |
| Isn't this information misleading?? The ignorant reader ( me) would
think that we're actally running Ethernet type packets on FDDI when
only 802 style packets are allowed.
Does the DEXFA driver remap ethernet packets into 802 SNAP packets
with OUI 00-00-00-pp-pp ?? so that they are bridgeable onto ethernet??
Is it just SDA that 'lies'??
Gullik
|
| 479.2 | | STAR::GAGNE | David Gagne - VMS/LAN Development | Wed Feb 19 1992 10:07 | 20 |
| re .1:
First, note that FDDI 802 packets with a PID of 00-00-00-pp-pp are
called Translated Ethernet packets.
In VMS, the name we give to "Translated Ethernet" packets is
"Ethernet" to match the CSMACD description.
This certainly makes it EXTREMELY easy for Ethernet applications to
port to FDDI - they have nothing to do but add FXA0 to their list of
supported devices. Many people were glad to know that it was this
simple to use the VMS FDDI driver(s).
This probably save Digital and third party vendors lots of time and
money.
I believe that calling an "Ethernet translated" packet just "Ethernet"
is okay. And in reality, we are just calling the port/channel
"Ethernet". So if you want to, feel free to say that VMS "Ethernet"
ports transmit and receive "Ethernet translated" packets.
|
| 479.3 | a bunch of answers | STAR::SALKEWICZ | It missed... therefore, I am | Thu Feb 20 1992 16:00 | 13 |
| Well,.. the term more in use is "Mapped Ethernet" rather than
"Translated Ethernet". The device name is DEMFA, not DEXFA or
DEFXA. The driver for the DEMFA builds a "Mapped Ethernet" header
which is 802 SNAP SAP, and PID of 00-00-00-pp-pp as you suggest.
There is no "conversion" from Ethernet to Mapped Ethernet,.. the header
is simply built correctly the first time.
The units for the Token Timers (T_Req, T_Neg, Restricted Token
Timeout, and TVX) is 80 nanoseconds,.. as viewed through SDA.
/Bill
|
| 479.4 | Translation/Mapping and Downstream Address. | STAR::GILLUM | Kirt Gillum | Fri Feb 21 1992 10:09 | 21 |
|
About the Upstream and downstream neighbor addresses, the driver will
only retrieve these addresses from the DEMFA as a response to a
NCP SHOW LINE MFA-? STA
I've also noticed that the downstream address appears to be missing
after this command. Maybe Bill could tell why. Perhaps the DEMFA does
not provide this information.
Why "Mapped Ethernet"? I think that the previous replies failed to
mention that "Mapping" was designed for the ability to communicate over
an extended lan. For instance, a bridge that bridges between the FDDI
ring and an Ethernet segment would map an Ethernet packet to have the
SNAP SAP 00-00-00-pp-pp format when forwarding to the FDDI ring from
the Ethernet. When forwarding from the FDDI ring to the Ethernet, the
SNAP SAP 00-00-00-pp-pp would be mapped to normal Ethernet.
This is discussed generally in the FDDI primer on page 117 (discussion
of 'Translating Bridges').
|
| 479.5 | | STAR::GILLUM | Kirt Gillum | Fri Feb 21 1992 10:15 | 7 |
|
Of course, I failed to mention that 802 packets flow through the
bridges without mapping/translation modification (if they are small
enough to fit on the Ethernet). Bridges will also automatically
fragment IP packets that are too large to go onto the Ethernet (great
feature).
|
| 479.6 | | KONING::KONING | Paul Koning, NI1D | Mon Feb 24 1992 11:43 | 16 |
| Re .0 item (1): are you sure the release notes say that? If so, that's a very
serious error.
We use 8 ms as the DEFAULT value of TTRT for good reasons (there's a paper by
Raj Jain that describes them in detail). There normally is no reason to change
TTRT, or, for that matter, any other settable parameter of FDDI. However, it
IS legal to change TTRT, in either direction subject to the limitations of
the FDDI standard (which are that TTRT must be between TMin and TMax, i.e.,
between 4 and 165 ms). It isn't normally worth the trouble to do so, since
neither increase nor decrease of TTRT has any significant effect on performance
in reasonable network configurations.
The same applies to the other settable parameters: they are settable because
the standard requires it, not because it makes any real sense to change them.
paul
|
| 479.7 | ayup | STAR::SALKEWICZ | It missed... therefore, I am | Mon Feb 24 1992 11:47 | 10 |
| re Kirt..
Yes,.. the DEMFA fails to supply the Downstream Neighbor Address
in the STATUS command.
perhaps one day,.. when the full GET SIF/NIF functionality gets
implemented.
/Bill
|
| 479.8 | | KONING::KONING | Paul Koning, NI1D | Mon Feb 24 1992 11:49 | 3 |
| Note that support for downstream neighbor address is required, not optional...
paul
|