Knowledge base Difference between Be and BT
We offer services that use BT and Be back-haul networks and exchange equipment. This page details some of the differences to help you decide if you would like BT, Be, or one of each.
BT services
BT have two types of exchange equipment, 20CN and 21CN and can also offer Fibre to the cabinet on their 21CN platform. The 20CN platform uses older exchange equipment (DSLAMs) with an ATM back-haul to Cisco or Juniper BRASs then IP back-haul via BTs 21CN MPLS core to us. The 21CN services use newer exchange equipment (MSANs) with IP back-haul to newer Redback BRASs and IP back-haul via BTs 21CN MPLS core to us. 20CN offers ADSL1 (up to 8Mb/s); 21CN offers ADSL2+ (up to 24Mb/s) with FTTC offering VDSL (up to 40Mb/s). BT offer Annex M, for faster upload on 21cn lines for extra cost.
Key advantages of BT based services
- We charge a lower base line cost for the BT services than Be, which can be cheaper for people that download very little such as light home users.
- BT is available pretty much everywhere in the country (Be only around 75% population)
- BT is used by many ISPs and so migration to us is often cheaper and quicker than with Be.
- BT offer FTTC (in very few places), though this has a 12 month minimum term.
Be services
Be have different exchange equipment (MSAN) with an IP Ethernet back-haul network that goes to BRASs and back to us over an IP back-haul network. Be offer ADSL2+ (up to 24Mb/s) with Annex M (up to 2½Mb/s uplink).
Key advantages of Be based services
- We provide more download for the same money on Be than BT making it cheaper for people that download a lot, such as businesses
- Be have targets for loss and latency and jitter in their network making it clear that they are prepared to operate an uncongested network. BT do not.
- Be have better settings typically allowing higher speeds than BT even on the same line (in some cases twice the speed).
- Be allow Annex M for much faster uplink as standard (BT offer this on 21cn for extra cost)
- Be are trialling seamless rate adaption to allow very stable lines even in varying line conditions (BT may trial this some time).
- Be allow direct control of line profiles with immediate effect (BT take a working day and only allow high level options to control the DLM. BT may change).
- Be do not run a DLM (dynamic link management) like BT do. This is often an advantage.
- Be do not run BRAS rate limiters which have to try and follow sync rate (BT do on 20CN lines, and it can be a pain).
- Be are trialling dual pair DSL (with specialised routers) for 40Mb/s speeds without FTTC.
Dual services
We can provide services where customers have two lines, one on BT and one on Be, with IP fall-back. This can provide higher availability services.
Technical Details
As of December 20th 2010, orders for Be lines will be PPPoA, with line settings matching BT.
| Feature | BT 20CN | BT 21CN | BE PPPoE (old) | BE PPPoA |
|---|---|---|---|---|
| ADSL1 | Yes | Yes | Yes | Yes |
| ADSL2+ | No | Yes | Yes | Yes |
| ADSL2+ Annex M | No | No | Yes | Yes |
| Line Management | DLM | DLM | Manual | Manual |
| MTU | 1500 PPPoA 1492 PPPoE | 1500 PPPoA 1492 PPPoE | 1492 PPPoE | 1500 PPPoA |
| VPI/VCI | VC 0/38 (PPPoA) LLC 0/38 (PPPoE) | VC 0/38 (PPPoA) LLC 0/38 (PPPoE) | LLC 0/101 | VC 0/38 |
The lower MTU may have implications for your network set-up and Internet access. Please discuss with support if you have concerns.
Whilst the login is the same, the router settings are slightly different (shame), notably PPPoE and VPC/VCI 0/101.
Note that seamless rate adaption (SRA) is in the pipe-line but not yet available.
Changing from BT to Be PPPoE
(not requred for new orders places after 20 December 2010, as these will be PPPoA) Key points if migrating from a BT to a BE line
- Use your full login of the username@a.1, username@a.2, etc. and not just username@a. Otherwise your login and password are unchanged.
- Change mux mode from VC to LLC
- Change VPI/VCI from 0/38 to 0/101
- Change encap from PPPoA to PPPoE
- Ensure the PPPoE service name is blank. This is often already set to AAISP or some such and should be blank.
- We suggest you check the control pages have the TCP option ticked for TCP MSS clamping.
- If you are bonding many lines, set all of them to have the MTU1492 and TCP option.
- If you are using a ZyXEL P660HW-T1 v2 (wireless) router, please see this Knowledge Base article.
