Other Line Options: Difference between revisions

Revision as of 18:56, 13 February 2016

Line Rate

This shows your line rate:

Line rate as shown on the control pages: 39.8M - Good!

This one has a rate of: 338K - Something is Wrong!

Changing the Line Rate

This sets the line rate on your line:

At 100%, the LNS throttles you to exactly your line's capacity. At 110%, it will let through 110% of your line capacity, and allow the wholesaler's systems to buffer/drop the excess. At 95%, it lets through 95% of the line's capacity, so it will be unaffected by the wholesaler's buffering. Setting to less than 100% is advised for lines running VoIP and other real-time services as it means the downlink won't be filled. Lowering the rate from 100% to 95% will mean that there should be no network buffering within the wholesalers network - and may well reduce latency when downloading at the full rate of the line.

At 100%, the LNS throttles you to exactly your line's capacity.

At 95%, it lets through 95% of the line's capacity, so it will be unaffected by the wholesaler's buffering.

Example:

Changing the rate from 100% to 95% reduces average latency when filling the downlink.

Stability Options

Available on BT 21CN ADSL

These stability options refer to how aggressive BT's DLM is when monitoring and managing the line.

Usually we would suggest keeping it on Normal (the default). Using increased stability options increases DLM sensitivity, so can have the side effect of making your line sync at lower speeds.

Other Line Options

Most of these options are available on all lines:

MTU

Forces an MTU regardless of what is negotiated by your router.

More Info: MTU is negotiated upon connection. We usually like 1500 MTU, however, there can be situations where forcing 1492 MTU is required. For example, if your router negotiated 1500 MTU initially but you make a connection to a server that want's to re-negotiate a lower MTU it will try to do this using ICMP, but if your router has a miss-configured firewall that blocks ICMP this can't be re-negotiated and the connection to the server will have problems. This is seen when connecting to certain web sites, bank web sites and https sites. Forcing 1492 MTU from the start means that all your traffic is in packets of 1492 bytes and so won't have this problem.

TCPFix

Modifies the MSS in TCP packets so that it does not exceed the MRU.

MRUFix

When sending IP traffic, ignore the MRU we receive during PPP negotiation. This can save a LCP re-negotiation, which has been known to help OpenBSD based PPP.

LCPFix

Re-negotiates PPP after acquiring the connection from BT, who may provide 1500 MTU when it should be 1492 MTU.

More Info: During the PPP connection when your router initially syncs up and logs in to us, the PPP connection is passed via BT. Sometimes BT can change the MTU. With this option we will accept the PPP connection from BT, but will then re-negotiate the PPP connection with your router allowing the MTU to be reduced. On TalkTalk connections the MTU is always negotiated as 1492 MTU, you will need to select LCPFix and 1500 MTU to fix this, otherwise the LNS will use 1492 MTU when re-negotiating.

FastTimeout

Uses an LCP Echo timeout of 10 seconds rather than 60 seconds before entering the LostCarrier state.

More Info: LCP echoes usually stop responding if the line has gone down. Our LCP monitoring, which produces the graphs will drop the line if there are no replies after 60 seconds. When bonding or used in a fall-back setup, having a faster timeout is useful in order to fall-back quicker.

Statistics and History

Sync History

Displays a list of your recent resyncs and the resulting sync speed and BRAS rate. This can be useful to view either if your line is regularly resyncing (bad!) or whether there is a deteriorating (or improving) trend in the sync speeds achieved.

Login/Logout

View other lines on your account that logged in or logged out at this same time (not very useful if you only have a single line though!)

Stats

Shows the recent usage/quality stats for the line, with columns: Time,Period,Polls Sent,Fail,Latency Min,Ave,Max,Traffic (bit/s) Rx,Tx,Score

The steps are normally 100s. Latency is in milli-seconds. The output is in CSV format for ease of import into a spreadsheet.

XML

The same as "Stats" above, but presented in XML to provide other processing options.

@@ Line 23: / Line 23: @@
 Example:
-[[File:Cqm-ratedrop.png|none|frame|Changing the rate from 100% to 95% reduced average latency when filling the downlink.]]
+[[File:Cqm-ratedrop.png|none|frame|Changing the rate from 100% to 95% reduces average latency when filling the downlink.]]
@@ Line 30: / Line 30: @@
 *Available on BT 21CN ADSL
-These stability options refer to how aggressiveness BT's DLM is when monitoring and managing the line.
+These stability options refer to how aggressive BT's DLM is when monitoring and managing the line.
-Usually we'd suggest keeping it on Normal (the default). Using increased stability options increases DLM sensitivity, so can have the side effect of making your line sync at lower speeds.
+Usually we would suggest keeping it on Normal (the default). Using increased stability options increases DLM sensitivity, so can have the side effect of making your line sync at lower speeds.
@@ Line 43: / Line 43: @@
 Forces an MTU regardless of what is negotiated by your router.
-'''More Info:''' MTU is negotiated upon connection. We usually like 1500 MTU, however, there can be situations where forcing 1492 is required. For example, if your router negotiated 1500 initially but you make a connection to a server that want's to re-negotiate a lower MTU it will try to do this using ICMP, but if your router has a miss-configured firewall that blocks ICMP this can't be re-negotiated and the connection to the server will have problems. This is seen when connecting to certain web sites, bank web sites and https sites. Forcing 1492 from the start means that all your traffic is in packets of 1492 bytes and so won't have this problem.
+'''More Info:''' MTU is negotiated upon connection. We usually like 1500 MTU, however, there can be situations where forcing 1492 MTU is required. For example, if your router negotiated 1500 MTU initially but you make a connection to a server that want's to re-negotiate a lower MTU it will try to do this using ICMP, but if your router has a miss-configured firewall that blocks ICMP this can't be re-negotiated and the connection to the server will have problems. This is seen when connecting to certain web sites, bank web sites and https sites. Forcing 1492 MTU from the start means that all your traffic is in packets of 1492 bytes and so won't have this problem.
 === TCPFix ===
@@ Line 55: / Line 55: @@
 === LCPFix ===
-[[File:LineOptionsLCPFix.png|none|frame|Re-negotiates PPP LCP after acquiring the connection from BT, who may provide an MTU of 1500 when it should be 1492.]]
+[[File:LineOptionsLCPFix.png|none|frame|Re-negotiates PPP after acquiring the connection from BT, who may provide 1500 MTU when it should be 1492 MTU.]]
-'''More Info:''' During the PPP connection when your router initially syncs up and logs in to us, the PPP connection is passed via BT. Sometimes BT can change the MTU. With this option we will accept the PPP connection from BT, but will then re-negotiate the PPP connection with your router allowing the MTU to be reduced. On TalkTalk connections the MTU is always negotiated as 1492, you need to select LCPFix and an MTU of 1500 to fix this, otherwise the LNS will use 1492 when re-negotiating.
+'''More Info:''' During the PPP connection when your router initially syncs up and logs in to us, the PPP connection is passed via BT. Sometimes BT can change the MTU. With this option we will accept the PPP connection from BT, but will then re-negotiate the PPP connection with your router allowing the MTU to be reduced. On TalkTalk connections the MTU is always negotiated as 1492 MTU, you will need to select LCPFix and 1500 MTU to fix this, otherwise the LNS will use 1492 MTU when re-negotiating.
 === FastTimeout ===
@@ Line 78: / Line 78: @@
 === Stats ===
-Shows the recent usage/quality stats for the line, with columns:
+Shows the recent usage/quality stats for the line, with columns: Time,Period,Polls Sent,Fail,Latency Min,Ave,Max,Traffic (bit/s) Rx,Tx,Score
-Time,Period,Polls Sent,Fail,Latency Min,Ave,Max,Traffic (bit/s) Rx,Tx,Score
-The steps are normally 100s. Latency is in ns. The output is in CSV format for ease of import into a spreadsheet.
+The steps are normally 100s. Latency is in milli-seconds. The output is in CSV format for ease of import into a spreadsheet.
 === XML ===