[BVC & MS flow control]

Hi,

Please tell me about the BVC & MS flow control for EGPRS network.

Is it usefull to enable this feature.

[C300G]

Well, it’s system that dynamicly controls two parameters of “Leaky bucket” algorithm: “Bucket size” and “Bucket leak rate”. This algorithm allows to smooth transmission rate in downlink direction. It basicly consists of transit buffer with size=”Bucket size” and transmission rate from that buffer to MS limited by value of “Bucket leak rate”. When buffer is full all inbound from ip-backbone ip-packets placed in queue on time that calculated by “Bucket leak rate”.
Strange… I always thought that this mechanism works by default.

[RF9]

Thanks C300G for ur reply.

Can u help me to understand the below BVC and MS flow control message:

1.)

Message Type: FLOW_CTRL_BVC(26)
The Tag to correlate request and response PDUs(1E)
The maximum BVC bucket size(MSB)(3510000 octets)
Bucket Leak Rate (R)(640000 bits/sec)
BVC Measurement(3510000 octets)
R_default_MS(640000 bits/sec)

Message Type: FLOW_CTRL_BVC_ACK(27)
The Tag to correlate request and response PDUs(1E)

2.)

Message Type: FLOW_CTRL_MS(28)
TLLI: 0xC704458F
The Tag to correlate request and response PDUs(00)
MS Bucket Size(6DB0)
Bucket Leak Rate (R)(0C80)

Message Type: FLOW_CTRL_MS_ACK(29)
TLLI: 0xC704458F
The Tag to correlate request and response PDUs(00)

Regards
RF9

[C300G]

#1:
>Message Type: FLOW_CTRL_BVC(26)
This PDU informs the flow control mechanism at an SGSN of the status of a BVC’s maximum acceptable SGSN to BSS
throughput on the Gb interface. Direction BSS/PCU -> SGSN.

>The Tag to correlate request and response PDUs(1E)
Some additional dialogue-id-tag.

>The maximum BVC bucket size(MSB)(3510000 octets)
Maximum intermediate buffer “Bucket” size for that BVC: 3510000 bytes.

>Bucket Leak Rate (R)(640000 bits/sec)
“Bucket Leak Rate” for that BVC: 640000 bits/sec.

>BVC Measurement(3510000 octets)
Something is wrong here. “BVC Measurement” must be measured in centiseconds, but not in bytes.
It looks more-like “Bmax default MS” parameter – default intermediate buffer “Bucket” size for a one subscriber-session on that BVC: 3510000 bytes.

>R_default_MS(640000 bits/sec)
Default “Bucket leak rate” for a one subscriber-session on that BVC: 640000 bits/sec.

>Message Type: FLOW_CTRL_BVC_ACK(27)
>The Tag to correlate request and response PDUs(1E)
Acnowledgement form SGSN on FLOW_CTRL_BVC message with that BVCI and Tag 1E.

#2:
>Message Type: FLOW_CTRL_MS(28)
This PDU informs the flow control mechanism at an SGSN of the status of an MS’s maximum acceptable SGSN to BSS
throughput on the Gb interface. Direction MS -> SGSN.
>TLLI: 0xC704458F
Subscriber session ID on BSSGP-signaling layer.

>The Tag to correlate request and response PDUs(00)
Some additional dialogue-id-tag.

>MS Bucket Size(6DB0)
Bucket buffer size for that MS-session: 2808000 bytes.

>Bucket Leak Rate (R)(0C80)
“Bucket Leak Rate” for that MS-session: 320000 bits/sec.

>Message Type: FLOW_CTRL_MS_ACK(29)
>TLLI: 0xC704458F
>The Tag to correlate request and response PDUs(00)
Acnowledgement form SGSN on FLOW_CTRL_MS message with TLLI 0xC704458F and Tag 00.

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