User's Manual

26
FiberGateway
Each of these Traffic Classes has an associated scheduler and policer. Queue management is
performed based on Tail Drop or WRED. Then Traffic Classes to P-bit remarking is done and the traffic
is sent to the uplink, Figure 11: Traffic distribution by service/client
.
Figure 10: Upstream QoS diagram
2.6.3 Dynamic Bandwidth Allocation (DBA)
The DBA (Dynamic Bandwidth Allocation) is available in order to optimize the upstream bandwidth. This
mechanism consists in defining an adequate T-CONT to the service traffic in question. There are five
types of T-CONT, defined by the Fixed, Assured and Maximum Parameters:
• Type 1: Only fixed Bandwidth;
• Type 2: Only Assured Bandwidth;
• Type 3: Assured+Maximum Bandwidth;
• Type 4: Only Maximum Bandwidth (Best Effort);
• Type 5: Fixed+Assured+Maximum Bandwidth
T-CONT
(Bandwidth)
Type 1 Type 2 Type 3 Type 4 Type 5 Uni.
Fixed - R
F
R
F1
0 0 0
R
F5
[b/s]
Guaranteed - R
A
0
R
A2
R
A3
0
R
A5
[b/s]
Maximum - R
M
R
M1
= R
F1
R
M2
= R
A2
R
M3
> R
A3
R
M4
R
M5
>
R
F5
+ R
A5
[b/s]
Bandwidth
Eligibility
0 0 Not Assured -
R
NA
Best effort -
R
BE
R
NA
/ R
BE
Tabel 1: T-CONT types definition
In each GPON interface there is 1024 Alloc-ID (T-CONT identifiers) available, provided to manage ONT
services. They are distributed in the following way: