| 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 |
Hi,
Followings are the questions on our DECbridge:
1. How big is the address table ?
The FDDI Technical journal says that the table size is '16K of
48bit addresses' while the NET U (August 1991) said that it only
has 14,000. So which one is correct ?
2. Does the forwarding rate depend on the number of entries in the
address tables ? Or the forwarding rate listed in our manual is
only the worse case figure ?
3. In NET U slide, it said that 'the DECbridge 6XX forward at a rate
of 22,200 packets per second' and 'the translation rate equates
to from 19,000 Minimum sized packets to 2,400 Maximum sized packets'.
It seems contradict as the worse case of forwarding rate should be
less than translation rate. So if translation rate is 19,000 pps,
the forwarding rate should be equal or less than 19,000 pps. So
am I missing something ?
4. The NET U slide said that 00-00-F8 will be used in OUI field for
the Appletalk packet, is it defined by Digital (proprietary ?) or
a standard body (which ?) ?
5. When will our DECbridge support SNMP 'write' ? What is the reason
of SNMP 'Write' not supported (NIS, DECbridge and even the DEChub)
?
6. How big is the FDDI and the NI module transmit/receive buffer ?
One of our customers asks for these information and they also
want to know how does the buffer size affect the network performance ?
(something like small buffer will have greater chance to lose packets
than large buffer). We need to answer these questions in the proposal.
Thanks for your help in advance.
Best regards,
Wing-Kin Leung
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 377.1 | KONING::KONING | Paul Koning, NI1D | Fri Oct 25 1991 14:19 | 17 | |
Partial answers:
2. Does the forwarding rate depend on the number of entries in the
address tables ? Or the forwarding rate listed in our manual is
only the worse case figure ?
>It's independent of number of entries.
4. The NET U slide said that 00-00-F8 will be used in OUI field for
the Appletalk packet, is it defined by Digital (proprietary ?) or
a standard body (which ?) ?
>A standard: Digital provided that OUI to IEEE 802.1, for use in a standard
>solution to the Appletalk problem (and others like it, if we ever see any
>others).
> paul
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| 377.2 | Hope this helps | QUIVER::HARVELL | Wed Oct 30 1991 10:15 | 40 | |
Here are a few more answers.
1. How big is the address table ?
The FDDI Technical journal says that the table size is '16K of
48bit addresses' while the NET U (August 1991) said that it only
has 14,000. So which one is correct ?
>
> The size of the complete lookup table is 16K however not all spaces
> are used for learned addresses. Therefore the amount of space that
> is available for learned addresses is 14K.
3. In NET U slide, it said that 'the DECbridge 6XX forward at a rate
of 22,200 packets per second' and 'the translation rate equates
to from 19,000 Minimum sized packets to 2,400 Maximum sized packets'.
It seems contradict as the worse case of forwarding rate should be
less than translation rate. So if translation rate is 19,000 pps,
the forwarding rate should be equal or less than 19,000 pps. So
am I missing something ?
>
> Because the DECbridge 6XX family are four ported bridges it is
> to have traffic that is going between the FDDI and the ethernet
> at the translation rate while other traffic is still being forwarded
> just between two ethernets. Only traffic that is going between an
> ethernet and an FDDI port are subject to translation.
>
5. When will our DECbridge support SNMP 'write' ? What is the reason
of SNMP 'Write' not supported (NIS, DECbridge and even the DEChub)
?
>
> Futures have to be discussed with the Product Manager.
>
No time to answer question number 6 right now I will try to get back to
it later.
Scott
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