Just tell me plz when to use Dialer profile

persona

To me ISDN is the hardest topic on CCNA. I would like to know when to use Dialer profiles.
TIA

tech-airman

persona wrote:

To me ISDN is the hardest topic on CCNA. I would like to know when to use Dialer profiles.
TIA

persona,

Do you understand how Legacy DDR works?

carveone

Never? Because it'll never come up?

Sorry. Couldn't help myself. ISDN is no longer part of the CCIE I believe and you can expect to be tested very lightly on it, if at all.

Having said that, you use a dialer profile if you have multiple destinations and one or limited lines. It's easy to imagine in the old days with a modem and multiple BBSes - to get your pron dial 1 and to get your warez dial 2 Um, you get the idea.

            /-------- Site 1
You  ------/
           \
            \-------- Site 2

You add lines to a dialer profile with dialer pool-member and then reference the pool from your dialer interface. When the interface needs a line it'll grab one from the pool. If one is not available it waits a fast timeout interval and then grabs the line.

interface bri 0
dialer pool-member 1
interface bri 1
dialer pool-member 1

interface dialer0
ip address 192.168.1.1 255.255.255.0
encapsulation ppp
dialer pool 1
dialer string 5551212

interface dialer1
ip address 192.168.2.1 255.255.255.0
dialer pool 1
dialer string 5551234

(I've left out a lot of stuff to simplify).

The ios knows which interface to use based on the route, normally added with a static route. For example.

ip route 192.168.1.0 255.255.255.0 192.168.1.2

Then when you want to visit the 192.168.1.0 network, it needs to go via 192.168.1.2, which is through interface dialer0, which uses dialer pool 1 and one of bri 0 or 1.

See? Hope this helps,

Conor.

carveone

In case it helps, the only way I could remember this stuff it with mnemonics. I used these:

NAT - iNside/outside, Accesslists, translation

ISDN - 3 under each letter except I for, uh, isdn!; switch-type/spid/static route; dialer map/dialer-group/dialer-list; eNcapsulation, name (for chap), no shutdown

Frame relay: "Limped": lmi, interface-dlci, map, pvc, encapsulation, dlci

Don't know if this helps anyone, but mnemonics are the way to go. No other way to remember the layers: APSTNDP: All people seem to need data processing.

Good luck,

Conor.

Grigsby

Someone tell me if I am wrong here but, as of 2007 isn't ISDN dead on the CCNA exam?

I didn't even see it on mine at the beginning of '06.

rossonieri#1

persona :
"I would like to know when to use Dialer profiles."

when you have multiple interfaces, and you have multiple destinations.

Grigsby :
"Someone tell me if I am wrong here but, as of 2007 isn't ISDN dead on the CCNA exam?
I didn't even see it on mine at the beginning of '06."

well, ISDN never dies i think.
the protocol maybe not so popular in north america - but the other part of the world depends on it heavily - and many other reasons why it stills exist - including rural areas that are not covered by DSL.

cheers.

Inc

ISDN is commonly used as backup link, where needed.

1. you define access list for "interesting traffic"
2. create dialer group for number to be dialed and map it to next hop IP
3. apply to interface

Spur

Inc wrote:

ISDN is commonly used as backup link, where needed.

1. you define access list for "interesting traffic"
2. create dialer group for number to be dialed and map it to next hop IP
3. apply to interface

I'll have to correct you here.

You define a dialer-list to determine interesting traffic. In the dialer-list you can link up an ACL in order to define what is "interesting".

The dialer-group tells the interface what dialer-list it should use to determine if the link should go up. The dialer map statement is used to define the name and the IP address of the remote router and here you also define the number to dial in order to get there. Dialer-group is not defined in the dialer map statement.

aquilla

rossonieri#1 wrote:

persona :
"I would like to know when to use Dialer profiles."

when you have multiple interfaces, and you have multiple destinations.

Grigsby :
"Someone tell me if I am wrong here but, as of 2007 isn't ISDN dead on the CCNA exam?
I didn't even see it on mine at the beginning of '06."

well, ISDN never dies i think.
the protocol maybe not so popular in north america - but the other part of the world depends on it heavily - and many other reasons why it stills exist - including rural areas that are not covered by DSL.

cheers.

Over here in Britain, British Telecom (BT) has announced today that it is to withdraw ISDN from consumer use later this year.

http://news.bbc.co.uk/1/hi/technology/6519681.stm

persona

tech-airman wrote:

persona wrote:

To me ISDN is the hardest topic on CCNA. I would like to know when to use Dialer profiles.
TIA

persona,

Do you understand how Legacy DDR works?

yes I do mate. I "understand" the idea behind it.

@carveone: Thx for your help.

same goes to spur..thx gents.

tech-airman

persona wrote:

tech-airman wrote:

persona wrote:

To me ISDN is the hardest topic on CCNA. I would like to know when to use Dialer profiles.
TIA

persona,

Do you understand how Legacy DDR works?

yes I do mate. I "understand" the idea behind it.

@carveone: Thx for your help.

same goes to spur..thx gents.

persona,

So you know that by using Legacy DDR, the BRI interface is pre-configured to connect with a single destination router, right?

persona

pre-configured? that's new.

I tried to use ISDN connection on a simulator. had to do the usual setting? A dialer list, and dialer map and so on.

Am I following what you mean or not?
thx 4 ur help.

rossonieri#1

aquilla wrote:

Over here in Britain, British Telecom (BT) has announced today that it is to withdraw ISDN from consumer use later this year.

http://news.bbc.co.uk/1/hi/technology/6519681.stm

well, ok -- thats new -- since many EU countries were the fans of ISDN,
but the fact is that technology keeps changing anyway.
thanks for the info.

cheers...

tech-airman

persona wrote:

pre-configured? that's new.

I tried to use ISDN connection on a simulator. had to do the usual setting? A dialer list, and dialer map and so on.

Am I following what you mean or not?
thx 4 ur help.

persona,

What I meant by "pre-configured" is that YOU need to configure Legacy DDR before the DDR actually works. No, I'm not talking about Dance Dance Revolution. :P

mgeorge

ISDN is no longer covered on the 801 exam, ALTHOUGH, expect xDSL technologies to be covered in the next CCNA update probably, it is already covered on the new CCNP exams in depth.

You will need to know IOS requirements, Dialer profiling, virtual circuits, diag commands, etc and standard ATM commands since xDSL is used over an ATM network.

Also ISDN has been removed from the CCIE and MPLS is favored to replace FR, Also, expect the new exams to get in depth with ATM medias which include OC, xDSL, T1 IMA's, etc...

Cisco obviously isnt doing a great job in keeping up with the current technology which is FTTH, "Fiber to the home" provided by Winstream Communications and Verizon "FiOS" (which are the only two I know doing it so far)

Obivously Cisco has no WIC's for this type of technology yet but it will use ATM formating and PPPoE Authentication, simular to a xDSL dialer and standard CHAP authentication.

So dont rule Dialer profiles out, they are just now getting started ^_^

rossonieri#1

hello mgeorge,

nice input

but I think what you have talked about really depends on the existing/established geographical location (countries) infrastructure or perhaps the providers section.
why cisco dont want to rush to put more advanced technology into CCNA probably because their vision of the CCNA certification itself is only to support 100 or less network user, and use existing basic technology.

correct me if i'm wrong.

cheers.

mgeorge

rossonieri#1 wrote:

hello mgeorge,

nice input

but I think what you have talked about really depends on the existing/established geographical location (countries) infrastructure or perhaps the providers section.
why cisco dont want to rush to put more advanced technology into CCNA probably because their vision of the CCNA certification itself is only to support 100 or less network user, and use existing basic technology.

correct me if i'm wrong.

cheers.

Well if you look at the countries that have not established a network infrastructure, they are considering "FTTH" fiber to the home, which can be also be upgraded without modifying the physical infrastructure. FTTH uses pppoe. although you are right with already established countries, but as technology advances, more and more established countries who are just now getting the internet are trying to find the easiest path to upgrade in the future with out the cost later down the road for physical infrastructure upgrades. Considering fiber can run any band width and is limited by the laws of physics, not electrothermodynamics such as copper.

Fiber was used at 10Mbps 10 years ago and today we can still use that same fiber to acheive 10Gbps speeds, get my point?

CCNA is in the general range of supporting up to 100 nodes yes, but you have to consider that 100 nodes counts for almost 70% of all businesses, not every business is as big as google, microsoft, ibm, dell, etc... their are more starter/small businesses then their are enterprises/large businesses.

One of the main reasons behind the updates to the CCNP tract was for service provider content, such as newer authentication methods, MPLS, new technologies and etc.. and with that being said you can easily conclude that the updated CCNA in the future will include to some extent, service provider content.

But my previous post was just to state that you CANNOT rule out dialer profiles because ISDN is being faded out, many newer technolgies still rely on many of the founder concepts such as authentication, encapsulation etc..

Teddy Rosevelt once said that "the more you know about the past, the better prepaired you are for the future."

rossonieri#1

mgeorge27 wrote:

Fiber was used at 10Mbps 10 years ago and today we can still use that same fiber to acheive 10Gbps speeds, get my point?

But my previous post was just to state that you CANNOT rule out dialer profiles because ISDN is being faded out, many newer technolgies still rely on many of the founder concepts such as authentication, encapsulation etc..

Teddy Rosevelt once said that "the more you know about the past, the better prepaired you are for the future."

i get your point . but the FO is our problem here in my country - besides its age - its has also being broken by same FO line digging activities by others.

the ISDN line why it still exist here mainly because the implementation of VoIP and other intranet - the FO-based DSL still rarely reachable by rural areas and we are largely separated by water - not like in the US continent.

and -- nice quote from Mr. Teddy.

cheers...