Tidy up

docs/lectures/acn/08_content_centric_networks.md

@@ -1,21 +1,23 @@
-# Content Centric Networks
+# Content-Centric Networks
 
 A Brief History of Networking
 
 - Gen 1. The **phone system** (focus on the **wires**)
-  - The utility of the system depends on running wires to every home & office.
-  - Wires are the dominant cost.
-  - A *call* is not the conversation, its the **PATH** between two end-office line cards.
-  - A *phone number* is not the name/address of the caller, its a **program** for the end-office switch fabric to build a path to the destination line card.
-  - <img src="img/k.png" alt="switch board" style="zoom:50%;" />
-  - Path building is **non-local** and **encourages centralisation** and **monopoly**.
-  - Calls fail is any element in the path fails so reliability goes down exponentially as the system scales up.
-  - Data cannot flow until the path is set up so efficiency decreases with setup time.
+    - The utility of the system depends on running wires to every home & office.
+    - Wires are the dominant cost.
+    - A *call* is not the conversation; it's the **PATH** between two end-office line cards.
+    - A *phone number* is not the name/address of the caller; it's a **program** for the end-office switch fabric to build a path to the destination line card.
+
+    - <img src="img/k.png" alt="switch board" style="zoom:50%;" />
+
+    - Path building is **non-local** and **encourages centralisation** and **monopoly**.
+    - Calls fail if any element in the path fails, so reliability goes down exponentially as the system scales up.
+    - Data cannot flow until the path is set up so efficiency decreases with setup time.
 
 - Gen 2. The **Internet** (focus on the **endpoints**)
-  - Data sent in independent chunks and each chunk contains the name of the final destination.
-  - Nodes forward packets onward using routing tables.
-  - **ARPAnet** was built on top of the existing phone system.
+    - Data sent in independent chunks and each chunk contains the name of the final destination.
+    - Nodes forward packets onward using routing tables.
+    - **ARPAnet** was built on top of the existing phone system.
 
 - Gen 3. **dissemination** (focus on the **data**)
 
@@ -30,10 +32,10 @@ A Brief History of Networking
 
 ###### Cons
 
-- *Connected* is a binary attribute. 
-- Becoming part of the internet requires a globally unique, globally know IP address that's topologically stable on routing time scales.
-  - Connecting is a heavy weight operation
-  - The net struggles with moving nodes
+- *Connected* is a binary attribute.
+- Becoming part of the internet requires a globally unique, globally known IP address that's topologically stable on routing time scales.
+    - Connecting is a heavyweight operation
+    - The net struggles with moving nodes
 
 #### Conversation and Dissemination
 
@@ -41,7 +43,7 @@ Acquiring chunks of data (web pages, emails, videos etc) is not a conversation,
 
 In a dissemination **the data matters**, not the supplier.
 
-- Data is request by name.
+- Data is requested by name.
 - Anything that hears the request, and has a valid copy can respond.
 - The return data is signed, so integrity and association can be validated.
 
@@ -63,33 +65,33 @@ Data packets are authenticated with digital signatures.
 
 #### CCN Forwarding
 
-Consumer *broadcasts* and *interest* over all available communication media
+The consumer *broadcasts* an *interest* over all available communication media.
 
 - e.g. `get '/parc.com/van/presentation.pdf'`
 - response: `heres '/parc.com/van/presentation.pdf/p1' <data>`
 
 ##### Names and Meaning
 
-* Like IP, CCN nodes imposes no semantics on names
-* Meaning comes from **application**, **institution** and **global conventions** reflected in prefix forwarding rules.
-* Globally meaningful name leveraging the DNS global naming structure
-  * `/parc.com/van/presentation.pdf`
-* Local and context sensitive, it refers to different objects depending on the room you're in.
-  * `/thisRoom/projector`
+- Like IP, CCN nodes impose no semantics on names
+- Meaning comes from **application**, **institution** and **global conventions** reflected in prefix forwarding rules.
+- Globally meaningful name leveraging the DNS global naming structure
+    - `/parc.com/van/presentation.pdf`
+- Local and context sensitive, it refers to different objects depending on the room you're in.
+    - `/thisRoom/projector`
 
 #### Strategy Layer
 
-* When you do not care who you are talking to, you don't care if they change
-* When you are not having a conversation, there's no need to migrate conversation state.
-* Multi-point gives you multi-interface for free.
-* When all communication is locally flow balanced, your stack knows exactly whats working and how well.
+- When you do not care who you are talking to, you don't care if they change
+- When you are not having a conversation, there's no need to migrate conversation state.
+- Multi-point gives you multi-interface for free.
+- When all communication is locally flow-balanced, your stack knows exactly what's working and how well.
 
 In the current Internet, Quality of Service (QoS) Problems are highly localised
 
-* Roughly half the problems are from serial dependencies created by queues
-* The other half are caused from a lack of receiver based control over bottle-necked links.
+- Roughly half the problems are from serial dependencies created by queues
+- The other half are caused by a lack of receiver-based control over bottlenecked links.
 
-Unlike IP, CCN is **local**, don't have queues and receivers have complete control
+Unlike IP, CCN is **local**, doesn't have queues, and gives receivers complete control.
 
 ![img](img/n.png)