WAN technologies

WAN

Requirements are
SLA
bandwidth
latency
loss

Cost
utilization.

Goals and policies
Applications and growth
budget


ISDN
BRI  - 128kbps
PRI  is 1.54 Mbps   like a T1.

DSL  mainly Async DSL

Cable   Cable Modem Termination System   CMTS

Wireless
Bridge is    point ot point
LAN  is   150 - 300 Mbps max
MObile     GSM ,      GPRS ,,    UMTS   3G    ,  LTE


FrameRelay.
PVC  permanent
SVC   switched just for the duration.

Sonet Circuit baed.
OC 1   51
OC 3  155
OC 12
OC 48

MPLS
Goal is to use labels instead of routing tables.
CE--> PE-->  P __> p  --> PE-->  CE

Dark Fiber is Point to Point

DWDM runs on the SONET and increases the ability to split ligh Lambdas.


CIR Commited infra
Burst  above

Same PPDIOO
Prepare
plan Desgin
implement operate
optimize.

Voice 250 ms
Video can afford to lose some pakcets    voice CAN'T

Private    Dark Fiber
Leased    TDM sonet
Shared    MPLS    framerelay.

Fixed cost  equipment and setup
recurring  are the monthly charges.

QoS
classify it based on protocol   or   a matching ACL.

Classification orr coloring.
Congestion management
Link Efficiecy    for low speed  to reduce latency and jitter
traffic shaping      use    ingress and egress flows.

Classification.
Identify and mark.  = classification
NBAR  can use layer 7 to recognize applications and then label them with a priority.
CAR    commited access rate. -- Basically match a traffic and then apply a priority

Congestion management
FIFO  first in first out
PQ  priority queiuing    sets up 4 levels.
     however   LEVEL High must be emptied before any of the other three are allowed.
     So if you have too much traffic at level High ,  the other traffic will suffer badly.

Custom Queuing      16  Queues, you can set up the queue limit.
                                  so when it is full.  The other queus get serviced.

WFQ   -  this is for interfaces below 2.0 Mbps .
               it creates two queues   -  high bandwidth.   low bandwidth.
              low gets service first.

Class Based Weighted Fair Queiuing.
SAme as WFQ   but you can use access list   and it is modular.


LLQ
Low Latency Queuing.
Basically  class based weighted fair queuing   +    PQ.
So voice EF gets serviced first         +   there is a limit on it.


Traffic Shaping.
Slowing down traffic so the utilization is high but consistent.
helps to curb    bursts into longer flows.


Policing.
Dropping traffic that passes a limit.




'Link Efficiency.
LFI   link fragmentation and interleaving   -   breaks up large packet flows and puts   small voip in between
MLP  multilink PPP     bonds links    like 2*T1
RTP   real time transport.    Compress the RTP   header from 40 bytes   to  2-5 Bytes.

Window Size.
Extend the Window size to allow more data in before you have to send an acknowledge.