Just re-reading your message Eric and it has lots of assumptions never made, such as your assumption the BTS doesn’t support the larger MTUs. That’s you reading into things that have not been said. The eNodeBs can do up to 1692, as can the EPC. The CPE is the bottleneck due to the chipset limitation of this current version.
Patrick Leary, Telrad 727-501-3735 From: Af [mailto:[email protected]] On Behalf Of Eric Kuhnke Sent: Friday, November 6, 2015 8:35 AM To: [email protected] Subject: Re: [AFMUG] Official Telrad response re MTU size I guess nobody ever thought that an ISP might ever want to deploy MPLS-capable edge routers at a CPE? Considering the cost of the CPE radios and the APs it's pretty weird they do not support a 1600 byte MTU. Before anyone says "MPLS customers should be on their own PTP link if they're such an important business", there are numerous use cases for an MPLS customer router on smaller branch office size sites. On Fri, Nov 6, 2015 at 4:50 AM, Patrick Leary <[email protected]<mailto:[email protected]>> wrote: Here you go folks. If this generates more questions, post them and I’ll seek more answers: Regarding the threads about MTU settings to run optimally, here is an official response: “In both WiMAX and LTE the UE is configured with an MTU setting of 1400. This will enforce either MSS clamping (TCP) , PMTUD (LAN side) or worst case fragmentation. The only time MTU becomes an issue is in bridge mode, in NAT mode the end user traffic will be working with a reduced MTU + encapsulation headers (28 bytes) i.e. GRE (WiMAX) GTP (LTE). Presently the Telrad BreezeWAY EPC can support 1918 and the eNodeB 1692. Regarding Telrad LTE UEs, the CPE7000 is limited to 1490 and the upcoming CPE8000 it will be 1560 (Patrick note: I cannot give an exact timeline on the CPE8000 beyond an expectation of end of Q1 2016, could be sooner); When working in bridge mode you can reduce the MTU of the LAN device or rely on the UE to fragment. Preventing fragmentation is optimal and this can be achieved by limiting the MTU side on the LAN device connected to the UE.” Cheers, Patrick Leary Telrad ************************************************************************************ This footnote confirms that this email message has been scanned by PineApp Mail-SeCure for the presence of malicious code, vandals & computer viruses. ************************************************************************************ ************************************************************************************ This footnote confirms that this email message has been scanned by PineApp Mail-SeCure for the presence of malicious code, vandals & computer viruses. ************************************************************************************ ************************************************************************************ This footnote confirms that this email message has been scanned by PineApp Mail-SeCure for the presence of malicious code, vandals & computer viruses. ************************************************************************************
