5305 (ALPHAserver 1200), switch, speed, full duplex etc

I'm still wondering whether I should buy a switch.

Normally, I have all my VMS machines (and one other machine) on a 10
Mb/s hub. The UPLINK port of that hub goes to a LINKSYS BEFSR41 DSL
router, which has a built-in switch. Also connected to that are a PC
and a VOIP-device. These run at 100 Mb/s, full duplex.

Each port has three LEDs. The top one (green) lights up when there is a
connection and blinks where there is traffic. The middle one (green)
lights up when things are full duplex and is otherwise dark, except that
it lights up when there are collisions. The bottom one (yellow) lights
up when the speed is 100 Mb/s.

My ISP has a "DSL speed checker":

http://www.1und1.de/index.php?page=speedtest

(beware of the non-linear scale).

I have a 6 Mb/s DSL connection. From the PC, where the 100 Mb/s and
full-duplex light up, the link above shows something like 6 Mb/s.
From a machine on the hub (old VAX, old ALPHA or 5305), it shows around
700 kb/s.

Today, before booting the 5305, I set EWA0_mode to FastFD at the
console and connected it directly to the switch. I got the following
message on the console while booting:

%EWA0, Possible duplex mode mismatch condition detected.

but otherwise things seem OK. The 100 Mb/s LED lights up on the switch,
but the full-duplex LED does NOT light up. Here's what VMS sees:

Device Characteristics EWA0:
Value Characteristic
----- --------------
1500 Device buffer size
Normal Controller mode
External Internal loopback mode
08-00-2B-C3-55-10 Hardware LAN address
Multicast address list
CSMA/CD Communication medium
FF-FF-FF-FF-FF-FF Current LAN address
128 Minimum receive buffers
256 Maximum receive buffers
Yes Full duplex enable
Yes Full duplex operational
TwistedPair Line media type
100 Line speed (mbps)
Disabled/No Failset Logical LAN state
0 Failover priority

Two things are confusing me. First, the speed test is STILL showing
only 700 kb/s instead of 6 Mb/s. Also, when I do the check, the
flashing of LEDs on the HUB increases markedly. Since the 5305 is
apparently running at 100 Mb/s (though probably not at full duplex) and
is directly connected to the switch, why can't I get more speed? Why is
this traffic apparently seen on the hub? Why doesn't the switch
indicate full duplex for the 5305? Also, and this is really confusing,
a PC on the HUB with a modern ethernet card shows the full 6 Mb/s EVEN
THOUGH IT IS CONNECTED TO THE HUB AND NOT DIRECTLY TO THE SWITCH. (Of
course, it is not part of the cluster.)

Thus, it seems that the reason the 5305 (and, perhaps the other nodes in
the cluster) are NOT getting the full DSL speed has nothing to do with
the switch: the 5305 (which has a modern ethernet card) is slow even on
the switch, and a PC (with a modern ethernet card) is fast even on the
hub. So, even though a switch might speed up SCS communication, it
seems that even with a switch I can't get the full speed with the 5305
and CAN get it with other machines even on the hub.

.

Relevant Pages

  • Re: 5305 (ALPHAserver 1200), switch, speed, full duplex etc
    ... Hawking 10/100 switch for $22.99. ... I have a 6 Mb/s DSL connection. ... From a machine on the hub, it shows around ...
    (comp.os.vms)
  • Re: 5305 (ALPHAserver 1200), switch, speed, full duplex etc
    ... Hawking 10/100 switch for $22.99. ... The UPLINK port of that hub goes to a LINKSYS BEFSR41 DSL router, ... These run at 100 Mb/s, ... The middle one lights up when things are full duplex and is otherwise dark, except that it lights up when there are collisions. ...
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  • Re: Backup to USB works but to NAS fails
    ... You've heard it before, but replace that hub with a switch as soon as possible. ... On windows it's a setting in the network card settings and usually ... Getting this up to 100Mb/s lan speed ...
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  • Re: Backup to USB works but to NAS fails
    ... On windows it's a setting in the network card settings and usually ... On a HUB ALL data is transmitted to ALL ports. ... Getting this up to 100Mb/s lan speed (either back-to-back or ... One switch is not the same as the next.. ...
    (microsoft.public.windows.server.sbs)