Subject: [nemo] Split Networks:Query

From: Sameer Kumar <[email-masked]>
Date: Wed, 17 Aug 2005 17:10:44 +0530

Hi all,

      I have a doubt regarding the concept of "Split Networks" in NEMO.
Split Networks comprise the case (n,1,1): Multiple MRs, Single HA, Single
MNP.

   Figure 1. below depicts the Split Network scenario. No "split" has
occured. MR1 and MR2 are together.

                        MR1

                      |  _  |

                      |-|_|-|  _____  

                      | p<- |-|     |  _   |  _

                   _  |     | |     |-|_|--|-|_|HA

               MNN|_|-|     | |     |  AR  |

                      |  _  |-|_____|

                      |-|_|-| INTERNET  

                      |p<-  |

                        MR2

              Figure 1: (n,1,1): Multiple MRs, 1 HA, 1 MNP

In this case, HA can send packets destined to MNN via MR1, or MR2 (Load
Balancing). The same situation in a wireless deployment is shown in Figure
2. Here also, we consider the case when no "split" has occurred i.e. MR1 and
MR2 are together.

                               AP1   MR1

                              _ _     _  |

                             / |_|---|_|-|  _____  

                          _ /  p<-       |-|     |  _   |  _

                      MNN|_|             | |     |-|_|--|-|_|HA

                                         | |     |  AR  |

                                _     _  |-|_____|

                               |_|---|_|-| INTERNET  

                              p<-        |

                               AP2   MR2

                     Figure 2: (n,1,1) : Multiple MRs, 1 HA, 1 MNP in a
Wireless Scenario

In Figure 2. MNN is currently attached to the Access Point (AP1) of MR1. I
have the following questions:

a)If HA tries to send packets to MNN via MR2, how will these packets reach
MNN? Basically how is "Load Balancing" 

  possible for a case (n,1,1) in a practical wireless deployment?

b)Is it that the AP1 and AP2 are "physically connected"? If so, then does
the term "split" means a "physical split"?

Thanks and Regards,

Sameer Kumar.

---

From: marcelo bagnulo braun <[email-masked]>
Date: Wed, 17 Aug 2005 15:21:33 +0200

Hi Sameer,

El 17/08/2005, a las 13:40, Sameer Kumar escribió:

> Hi all,
>       I have a doubt regarding the concept of "Split Networks" in 
> NEMO. Split Networks comprise the case (n,1,1): Multiple MRs, Single 
> HA, Single MNP.
> In this case, HA can send packets destined to MNN via MR1, or MR2 
> (Load Balancing).

so far so good

>  The same situation in a wireless deployment is shown in Figure 2. 
> Here also, we consider the case when no "split" has occurred i.e. MR1 
> and MR2 are together.
>  
>  
>                                AP1   MR1
>                               _ _     _  |
>                              / |_|---|_|-|  _____ 
>                           _ /  p<-       |-|     |  _   |  _
>                      Figure 2: (n,1,1) : Multiple MRs, 1 HA, 1 MNP in 
> a Wireless Scenario
>  

I am not sure i understand this scenario...
I mean as i see this case 2, the network has already split and in order 
to deal with this situation, you would need additional mechanisms, 
since MR1 and MR2 only connect themselves through the internet (i.e. 
the nemo is split)

In this case the difficulty is to detect that the nemo has split and to 
be able to determine which MNN are in which part of the nemo, 
especially when you have a single MNP. For this you would need 
additional mechanisms and/or to impose certain contraints, like 
requiring that each MR has its own prefix assoicated, so that when they 
split, the MR can take its MNP with it. /this configuration is not 
without problems of its own, like ingress filtering compatibility and 
so on)

so...

> In Figure 2. MNN is currently attached to the Access Point (AP1) of 
> MR1. I have the following questions:
>  
> a)If HA tries to send packets to MNN via MR2, how will these packets 
> reach MNN?

they can't without additional mechanisms imho

>  Basically how is "Load Balancing"

not sure what you mean

> b)Is it that the AP1 and AP2 are "physically connected"? If so, then 
> does the term "split" means a "physical split"?
>  

AP1 and AP2 are connected through the internet and not thorugh the nemo 
as i see it, so they don't belong to the same nemo, that is why they 
are split

regards, marcelo

---

From: Sameer Kumar <[email-masked]>
Date: Wed, 17 Aug 2005 19:27:27 +0530

Hi Marcelo,
           Thanks for the prompt reply. I think I couldn't convey my
question clearly in my last mail. Let me put it this way:
- In case of a wireless network ( case (n,1,1)) with MR1 advertising through
AP1, and MR2 advertising through AP2, and "NO SPLIT" has occurred, how is it
possible for an MNN to receive packets from both MR1 and MR2?

I just want to clarify how an (n,1,1) network is deployed in a wireless
scenario such that MNN can receive packets from all the MRs.

Thanks and Regards,
Sameer Kumar.

-----Original Message-----
From: marcelo bagnulo braun [mailto:[email-masked]] 
Sent: Wednesday, August 17, 2005 6:52 PM
To: Sameer Kumar
Cc: [email-masked]
Subject: Re: [nemo] Split Networks:Query

Hi Sameer,

so far so good

so...

not sure what you mean

regards, marcelo

---

From: marcelo bagnulo braun <[email-masked]>
Date: Wed, 17 Aug 2005 16:45:28 +0200

El 17/08/2005, a las 15:57, Sameer Kumar escribió:

> AP1, and MR2 advertising through AP2,

I guess i am failing to understand the scenario... let me ask: are MR1 
and MR2 connected through the nemo or are only connected through the 
Internet?

Regards, marcelo

>  and "NO SPLIT" has occurred, how is it

---

From: Chan-Wah Ng <[email-masked]>
Date: Thu, 18 Aug 2005 10:45:50 +0800

Hello Sameer and Marcelo,

> possible for an MNN to receive packets from both MR1 and MR2?

Nope, its already split.  True, MR1 and MR2 are on the same access
network link, but by splitting into AP1 and AP2, you created two
different *Mobile Network Links*.  So, it is actually something like
that:

                   Mobile         Access
                   Network        Network
                    Links          Link
          +--------+                 |
          | NEMO-1 +--- AP1 -- MR1 --+
          +--------+                 |
                                     + -- AR -- Internet -- HA
          +--------+                 |
          | NEMO-2 +--- AP2 -- MR2 --+
          +--------+                 |

/rgds
/cwng

---

From: marcelo bagnulo braun <[email-masked]>
Date: Thu, 18 Aug 2005 04:43:04 +0200

This is my understanding too