Priscilla,
Thanks. High praise considering the source. ;-)
The reason the telephone number is mapped to the MAC is so that the
number follows the DEVICE on the network. Please note that I stated that
the IP phone "identified" itself to the CM by announcing its MAC address.
If you leave Extension Mobility out of the equation, it is a pretty
ironclad way to guarantee that the phone number assigned to the phone
will be consistent even if the phone moves to a new network segment, ANY
network segment that can route IP traffic to the CallManager.
Bruce
Priscilla Oppenheimer wrote:
Great answer. Finally an explanation that makes sense for the marketing
babble about IP Telephony making Moves, Adds, and Changes easier. ;-)
One quesiton though, does CallManager really care about MAC addresses?
Unless the receiving phone is on the same network segment as the calling
phone, the MAC address won't help matters. ARP would take care of getting
the MAC when it's needed.
Priscilla
Bruce Enders wrote:
B. J.
The only trick here is to remember that the User phone number
"1111" is
"mapped" to the MAC address and IP address of the ethernet
interface
associated with the hard phone, or the laptop in the case of
Softphone.
(Both are PCs running specific applications software). Whenever
either is
disconnected from the network long enough for link to drop,
they have to
check in with DHCP when they are re-connected to the network.
Both also
have to check in with their CallManager. During that process,
they
identify themselves using their MAC address, and announce their
current
IP address. After that, the CM can simply forward based on the
IP
address. This capability is one of the primary reasons that
Moves, Adds,
and Changes in an IP Telephony system are far more simple than
in a
legacy PBX environment. (The logic behind your response sounds
like it
comes from the legacy telephone world, which is very used to
working in a
very static addressing environment).
Bruce
B.J. Wilson wrote:
Hi Vance -
I too am studying All Things VoIP, and I'm curious how
this would work.
Say you have User A trying to call User B. User B is
currently in the
office. So User A dials '1111' which is User B's phone
number (or "route
pattern" if you want to be specific). CallManager picks up
the route
pattern, looks up User B's location, and forwards the call
on. All is good.
Now, say User B is telecommuting. How does CallManager
know this? How
does your RAS (remote access) server notify CM that User B's
geographical
location has moved? Is there something in User B's RAS
(Registration,
Admission and Status) setup that alerts CM to the fact that
they're dialing
in from home?
Thanks,
BJ
----- Original Message -----
From: "Vance Krier"
To:
Sent: Wednesday, October 16, 2002 4:08 AM
Subject: Re: VoIP Clarification. [7:55682]
Hey Stu,
In simple terms, yes you are correct. However, as I'm sure
you know, you
need to take this type of setup with a grain of salt. If
you have a
decent
bandwidth, low latency, consistent connection between the
phone and CM, it
works fine. There's absolutely no guarantees for QoS on
the Internet.
Now, FWIW, I use softphone on my laptop when I travel and
I've gotten
satisfactory results (IMO) better than 75% of the time.
I always pitch this as being a *kewl* feature, but never as
a selling
point.
I'm
very, very cautious with customers over this. As long as
the user
using it is understanding and realizes there will be times
when it doesn't
work or the quality is really crappy, then typically they
stay happy. Not
something I'd give to Internet/computer/technology
illiterate executive.
I love it, by the way.
Good luck,
Vance
""Stuart Pittwood"" wrote in message
news:200210160746.HAA10542@;groupstudy.com ...
Good Morning all,
I am just starting to look into VoIP as I have been asked
by my manager
to
do some research and find out if there are any benifits
from VoIP for
our
firm.
Am I right in saying that if we had a solution based on
Cat 6000 (or
similar) switches, with a cisco VPN solution for the home
workers, that
users who use their laptop at home with cisco softphone
or hardware
phone
could have their telephone extenstion follow them?
Please forgive the simplicity of my question, just making
sure I am
thinking
along the right lines.
Thanks
Stu
--
Bruce Enders Email:
[EMAIL PROTECTED] Chesapeake NetCraftsmen
o:(410)-280-6927, c:(443)-994-0678
1290 Bay Dale Drive, Suite 312 WWW:
http://www.netcraftsmen.net Arnold, MD 21012-2325
Cisco CCSI# 96047
Efax 443-331-0651
--
Bruce Enders Email: [EMAIL PROTECTED]
Chesapeake NetCraftsmen o:(410)-280-6927, c:(443)-994-0678
1290 Bay Dale Drive, Suite 312 WWW: http://www.netcraftsmen.net
Arnold, MD 21012-2325 Cisco CCSI# 96047
Efax 443-331-0651
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=55796&t=55682
--------------------------------------------------
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
