Subject: [NEXTEL-1] Re: Nextel Spectrum 'Grab' Will be asetback......

From: [email-masked]
Date: Mon, 28 Jun 2004 19:29:11 -0400

Steve Gehring wrote:

> Marcel,
>
> Please explain to me why Direct-Connect calls would be routed via an
> intra-LATA tandem switch?

Direct-Connect calls are NOT  routed via a standard intra-LATA tandem switch. I
did not mean to imply DC is routed through the tandem switch.

MSO's with Tandem switches usually support large areas and require double and
some times triple the amount of transport resources than a single switch.  As
you know dispatch calls are voice communications that use the half-duplex
Push-To-Talk(PTT) form of communication. This type of call uses other provider
networks for transport facilities only. These calls may cross service areas if
the DAPs of both service areas are networked together and have shared
processing. Networking the DAPS is where the extra capacity is required.

The Metro Packet Switch (MPS) performs the cross connect functions under DAP
control. The MPS connects to the EBTSs over transport facilities. Connections
between the DACS and the MPS are T1 (but can be larger depending on config). The
MPS has no OMC-R link. Control and routing from the DAP is exchanged over T1/E1
links using Frame Relay.

> Gee, I would think direct-connect calls would
> remain on Nextel's ATM backbone network -- connected via leased lines?
> Heck, I would believe all direct connect calls would never leave their
> network.  That's how I'd design their network.

Direct-connect calls pass through Sprint's, MCI's and other facilities via
leased lines. As you know these leased lines are subject to outages just as the
PSTN.

>
>
> BTW, properly routed intra-LATA PSTN calls to a tandem switch will be
> determined by the npa-nxx and referenced (routed) according to the local
> exchange routing guide (LERG).

Yep, I use to work for a large CLEC, I had to deal with all kinds of npa-nxx
issues, and I was on the RF end!
We use to have a cool npa-nxx look-up for cellphones that told us which carrier
it belonged to.

> Note: I used to do transport engineering,
> network optimization, and least cost routing for wireless carriers as an
> employee and consultant.

I had 2 transport Eng that supported my  LMDS and P2P operations, I always had
my RF links in place long before transport was done. You guys had it tuff
dealing with the vendors. The conf calls got soo nasty.....can you say ESCALTE?

>
>
> But, my understanding of their network could be off... I could be all wet.

No you are pretty close.

> Chow,
> Steven