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Re: (ASCEND) Lucent -=-> Ascend --> ? (fwd)

Once upon a time Jason Nealis shaped the electrons to say...
>In relation to the PM4 and TNT, What truly is the advantage of 
>the PM4 over the TNT? If it's modem ports, I'm sure the next generation

Jason asked, I'm answering.  If you don't want to see a data dump on the PM-4,
I'd skip the rest.

The TNT has a 155Mbps backplane - the PM-4 has a 5Gbps ATM backplane, a 
minimum of 155Mbps PER SLOT.  10 slots.

155Mbps	155Mbps	155Mbps	155Mbps	manager	155Mbps	622Mbps	155Mbps	155Mbps 155Mbps
			special		manager

The 'special' slot has additional connectors, it has been designed for a
3 T3 demux card, the next level for the PM-4.  The 5th slot is dedicated to
the management card.  The 6th slot is a standard slot OR a backup manager
card, the 7th slot cango to OC-12, it has a 622Mbps connection.

Right now a PM-4 with 9 media cards and 1 manager card can take 864 DS0s -
all 864 can be modems, ISDN, etc.  Each media card is self containted with
4 T1s and 98 modems (they included 2 spares on board).  The next generation
is supposed to triple that to 12 T1s on a card.

To use T3 you can install a T3 demux card and 7 media cards for 672 modems.
With the management card there is a slot left for whatever.

Next gen would be the 3 T3 demux card and 7 of the higher density cardcs for
2016 modems in one chassis.  I really expect anyone putting that many eggs
in one basket to use the remaining slot for the backup management card.

The next step, if the market ever supports it, would likely be a T3 AND modems
on a single card.  That is a somewhat frightening thought.  And the PM-4
has the ability to handle *three* T3s PER SLOT.

Now, the TNT webpages still say a max of 288 modems per chassis - isn't that
out of date.  I thought they can to 672 (A t3) with TWO chassis now, which
implies at LEAST 336 per chassis.  Jason, didn't you tell me the TNT upped
modem density beyond 288?  Of course the webpages also still say the TNT does
BGP. ;-)  <URL:http://www.ascend.com/621.html>

Other interfaces that are coming as DS3 and OC-3 for ATM, SONET, etc.  xDSL
is in the works - I expect to see a WildWire server card.  VOIP/FOIP is in
the works.  The next generation of Lucent DSP, the 16000 series (the current
are the 1600 series), is being used by both their VOIP/FOIP people and the
modem people.  The expectation being that the same card will be able to
do either service, strictly a software issue.  A dedicated T3 (as in not a
demux card, but a T3 card designed for non-modem use - HDLC/ISDN, leased lines,
etc only) is a safe bet.  And the 100baseTX ethernet is already a daughter
card on the management board that speaks 155Mbps ATM to the main card.  It
would just be a form factor change to produce a 100baseTX media card as a
stand alone.  Oh, and the 100baseTX port is full duplex. ;-)  A processor
card is also expected - designed to be a dedicated work horse for tunneling
and encryption, and anything else that might require a lot of CPU.  Right
now there is a 4 port NO modem card - basically the modem card without any
of the DSPs for leased line or ISDN only work, and there is talk of a 10 or
12 port NO modem card to follow.  That would just be cloning the existing
traces I'd expect - 12 ports with modems is more work, as it is waiting on
the higher density DSPs

Oh, there is a three E1 card and an E3 demux too, for those who need them.

And remember ComOS is ComOS - RIPv1, OSPFv2 with NSSA, BGP4, Frame Relay, PPP,
BACP, L2TP, IPIP, NAT - everything - is included.  No options.  I believe
IPSec encryption - now in beta on the PM-3 with the MIPS Accelerator board -
is waiting on the processor board.  Stac, a daughter card option on the 
PM-3, is just included.  The media cards have integral Stac HiFn chips.
It is also a distributed routing architecture.  The management card runs
the active protocols, but distributes the routing lookup tables to the
other cards, which have their own route processors.  So if traffic is 
coming in and out of WAN ports, it doesn't need to go via the management
card.  Cooling is lower front to upper rear - no worries about exhaust
heating the next box over.  N+1 power supply design, 3 small hot swappable
units, 1 needed for each 5 slots, the 3rd is backup.  The entire chassis is
-48vDC native, so if you are in a telco space with DC on the rack you can
connect right up, no power supplies required at all.

The TNT can support more T1 ports for Frame Relay - 150 (15 FrameLine
Modules).  Even with a 12 port card the most a PM-4 can do is 108.  The
problem isn't data - it is physical space.  12 T1 ports will pretty much
fill the media card edge to edge.  To do more they'd have to create a
custom connector and some kind of fan out cable.  I don't know that that
is worth the trouble.  Also the PM-4 ports aren't Frame Relay only - it
is more like the 8 port channelized T1 cards for the MAX - FR, ISDN, 
leased line PPP, etc.

-MZ
-- 
<URL:mailto:megazone@megazone.org> Gweep, Discordian, Author, Engineer, me..
Join ISP/C Internet Service Providers' Consortium <URL:http://www.ispc.org/>
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